United CoolAir VertiCool CLASSIC User manual

VertiCool™ CLASSIC
Single Package Vertical Unit (SPVU)
Installation, Operation and Maintenance Manual
Effective June 2017
Air-Cooled, Water-Cooled,
Chilled Water and Water Source Heat Pump

Installation, Operation and Maintenance Manual
VertiCool Classic
3
Subject to change without notice. 20.10-IM (0617)
Contents
Important Notice ������������������������������������������������������������������4
Use of Symbols �������������������������������������������������������������������4
General Information�������������������������������������������������������������5
Inspection Of Equipment �����������������������������������������������������5
Handling ������������������������������������������������������������������������������5
Mounting And Setting In Place ��������������������������������������������5
Unit Vibration Isolation���������������������������������������������������������6
Location�������������������������������������������������������������������������������6
Clearance ����������������������������������������������������������������������������6
Louver And Ducting �������������������������������������������������������������6
Length of Ductwork for Discharge Air����������������������������7
Application Data ������������������������������������������������������������8
Installation ���������������������������������������������������������������������������8
Air-Cooled Single Package �������������������������������������������8
General Ductwork Recommendations ��������������������������9
Plenum Installation ��������������������������������������������������������9
Condensate Drain Connection ��������������������������������������9
Refrigerant Connections������������������������������������������������������9
Electrical����������������������������������������������������������������������������10
Transformer �����������������������������������������������������������������11
Wiring �������������������������������������������������������������������������������11
Three Phase Power�����������������������������������������������������������11
Electric Heat ����������������������������������������������������������������������11
Voltage Unbalance �����������������������������������������������������12
Chilled Water Coil Valves Or
Hot Water Coil Valves��������������������������������������������������������12
Pressure Switches ������������������������������������������������������������12
High Pressure / Low Pressure�������������������������������������12
Water-Cooled Units �����������������������������������������������������������12
Water Piping and Connections �����������������������������������13
Chilled Water Sections ������������������������������������������������������13
System Options �����������������������������������������������������������������14
Humidier ��������������������������������������������������������������������14
Auxiliary Coils (Hot Water or Steam)���������������������������14
Water Side Economizer (Free Cooling Coil)����������������14
Air Side Economizer����������������������������������������������������14
Split Systems���������������������������������������������������������������������15
Evaporator Mounting ���������������������������������������������������15
Interconnecting Refrigerant Tubing �����������������������������15
Condensate Pump�������������������������������������������������������17
Controls �����������������������������������������������������������������������������18
Thermostat ������������������������������������������������������������������18
Microprocessor Controller �������������������������������������������18
Flooded Condenser�����������������������������������������������������������18
Maintenance Procedures���������������������������������������������������19
Filters���������������������������������������������������������������������������������19
Cleaning The Water-Cooled Condenser����������������������������19
Blowers������������������������������������������������������������������������������19
Blower Motors��������������������������������������������������������������������19
Blower Speed Adjustment �������������������������������������������������20
Blower Bearing Lubrication������������������������������������������������20
Belts�����������������������������������������������������������������������������������20
Refrigerant Systems����������������������������������������������������������21
Evaporator And Air-Cooled Condenser Coils ��������������������21
Finned Coil Cleaning ���������������������������������������������������21
Water Side Economizer Coil����������������������������������������22
Water Valves ���������������������������������������������������������������22
Hard Start Kit���������������������������������������������������������������22
Checking Hot Gas Bypass Valve���������������������������������22
Adjustment Of Hot Gas Bypass Valve�������������������������22
Sequence Of Operation Cooling - - Air-Cooled �����������23
Cooling - - Water-Cooled���������������������������������������������23
Cooling - - Chilled Water ���������������������������������������������23
Heating (Other Than Heat Pump) �������������������������������23
Heating (Heat Pump, Water Source)���������������������������23
Troubleshooting Guide ������������������������������������������������������24
Limited Warranty ���������������������������������������������������������27–30
Air-Cooled Unit �����������������������������������������������������������������31
Start-Up Procedures (R-410a Systems)����������������������������31
Optional Heating Start Up: ������������������������������������������32
Air-Cooled Unit �����������������������������������������������������������������33
Start-Up Procedures����������������������������������������������������33
Cooling Mode ��������������������������������������������������������������34
Electrical����������������������������������������������������������������������34
Heating Mode (Optional) ���������������������������������������������34
Water-Cooled Unit ������������������������������������������������������������35
Start-Up Procedures (R-410a Systems)����������������������������35
Optional Heating Start Up: ������������������������������������������36
Water-Cooled Unit ������������������������������������������������������������37
Start-Up Procedures����������������������������������������������������37
Cooling Mode ��������������������������������������������������������������38
Electrical����������������������������������������������������������������������38
Heating Mode (Optional) ���������������������������������������������38
Verticool Classic Basic Model Designation������������������������39
LIMITED WARRANTY�������������������������������������������������40
FACTORY TESTED ����������������������������������������������������40

Installation, Operation and Maintenance Manual
VertiCool Classic
4
Subject to change without notice. 20.10-IM (0617)
Important Notice
The electrical hazard icon indicates the presence of an electrical hazard which
could result in electrical shock or death�
The warning icon indicates a potentially hazardous situation which could result
in death or serious bodily injury if not avoided�
The caution icon indicates a potentially hazardous situation which may result in
minor or moderate injury if not avoided�
The information icon indicates a situation that may result in equipment or
property damage� The information provided alerts the reader to relevant facts
and/or conditions�
ELECTRICAL
HAZARD
WARNING
CAUTION
INFORMATION
This publication includes warnings, cautions and information icons that point out safety related issues or conditions as well
as other pertinent information relative to a safe installation, service or maintenance situation� The following icons should be
interpreted as follows:
This manual is the property of the owner.
Please be sure to leave it with the owner when you leave the job.
Use of Symbols

Installation, Operation and Maintenance Manual
VertiCool Classic
5
Subject to change without notice. 20.10-IM (0617)
General Information
Inspection Of Equipment
Upon receipt of the unit, inspect for visible or concealed
interior / exterior damage� Report any damage to the carrier,
and le a damage claim.
Inspect the unit data plate to verify the model unit that was
ordered is what has been received�
Some options / accessory items may have been shipped
loose in one or more boxes� These may have been delivered
to another location, or possibly within the unit� If shipped with
the unit there will be a sticker that identies where in the
unit the shipped loose items are located. Conrm that all of
these options / accessory items are also available and that
no damage has occurred�
Handling
To facilitate handling, the unit is set on a wooden skid so
that it may be picked up with a two-wheel hand truck or fork
lift� Under no circumstances should the unit or the skid be
“walked” on the corners� Use dolly trucks, pipe rollers or
suitable means to move the unit to its proper location�
If a crane, cables or slings are used to move a unit or module,
spreader bars must be used to protect each section’s
cabinet structure� Some units or modules will be provided
with either lifting eyelets or brackets that should be used to
lift the sections�
When vertical style units are shipped split, or will be split in
the eld and then reassembled in the space, the condensing
section has refrigerant lines that extend above the top of the
cabinet�
When the unit is assembled these ttings are recessed into
the evaporator section . These ttings extend approximately
5” for all models (Figure 1)�
The space height needs to be sufcient to handle not only
the combined unit height, but also the refrigerant tting
clearance height�
Figure 1
Mounting And Setting In Place
CAUTION
Unit should not be located in space subject
to freezing temperatures�
The VertiCool Classic has been designed to be installed as
a single package oor mounted unit.
Unit is to be mounted on a solid oor or supported on a
full 100% perimeter frame. Attention must be given to oor
loading limitations� Floor should be level in both horizontal
planes�
Before the unit is installed, a thorough study should be made
of the structure and proposed installation location� Careful
consideration must be given to location of wiring, condensate
disposal, ductwork and accessibility for maintenance
or service� It is necessary that a minimum clearance of
36” be allowed on the front of the cabinet� Some air path
congurations will also require side access to the evaporator
section. Sufcient clearance must be provided to slide the
air lter(s) out, either the left or right side.
Consideration must be made for condensate removal, either
with a trap or condensate pump�
The units might be shipped as a single package or they
might be shipped split� Units that have been ordered with
the optional resealable refrigerant ttings can be split in the
eld to accommodate moving into position. Sections are
also bolted together�
When re-assembling the evaporator section to the
condensing section, use a sling or other suitable means that
is sufcient to hold the weight of the section. Use spreader
bars to keep the cabinet from being deformed�
Make sure that the evaporator section is positioned correctly
for the desired air pattern� Care must be taken when lowering
the evaporator section that the refrigerant resealable ttings
are lined up properly and that they are not damaged in this
process� Re-install the fasteners if removed prior�
5"

Installation, Operation and Maintenance Manual
VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
Unit Vibration Isolation
When installing any oor mounted unit, it is generally not
necessary to provide any unit vibration isolation� However,
some form of vibration isolation may be requested� Please
note that the unit frames have not been designed for corner
point only loading with vibration isolation methods�
1. If spring mounts are to be used, fabricate a frame to
provide support around the entire perimeter of the unit�
Allow sufcient clearance for any door or panel access
that is required to provide eld service or maintenance
on the unit� The frame will also need to be designed
with suitable cross bracing� (Figure 2)
2. If wafe pad or other similar sound vibration materials
are going to be used, the material needs to be placed
under the entirety of the unit base�
Figure 2
Location
Strategically located intake and discharge louvers help to
prevent recirculation of discharge and contaminated air
into the intake air stream. Airow around a building and
prevailing wind direction can adversely affect the potential for
recirculation and should be factored into louver placement�
In some areas, local codes dictate louver location� Maximize
the distance of intake louvers from any exhaust outlet and
other contaminants, people, property lines, etc� Avoid placing
intakes near idling vehicles�
The bottom of the intake louver should be raised a minimum
of 12" from a horizontal surface (roof, sidewalk, etc�) to
prevent blockage from debris� If snow accumulations are
expected to be greater than 12", raise the bottom of the
louver above the average snowfall depth�
If more than one VertiCool unit will be installed in the same
area, then the minimum separation of one unit adjacent
to another should be 6 feet� A 10 foot separation distance
should be maintained where two units are installed one
above the other� It is best to direct discharge air up and away
from pedestrian walkways as well�
We do not recommend multiple installations between closely
situated buildings where discharge air could collect and be
directed back to the intake� Again, recirculation will cause
the unit to trip on high head pressure�
Clearance
Clearance of 36" is required on the front side of all units for
service and maintenance access�
If a unit has front return, 30" clearance on each side of
the unit must be provided for access to the motor and / or
refrigerant circuit components, such as the thermostatic
expansion valve(s)�
Filters can be accessed from either side of the unit. Sufcient
space must be provided for removal and replacement of all
lters. This can be from one side only or from both sides.
Louver And Ducting
Carefully choosing the right condensing section intake/
exhaust louver(s) and determining the best location for them
are critical components to a successful VertiCool installation�
and/or discharge unit openings to allow for optimum velocity
and reasonable pressure drop across the louver�
1. Select a louver design that will safely separate the
discharge from the intake air stream to ensure that air
recirculation will not occur�
2. The intake louver should be designed to minimize and
virtually eliminate water penetration at a reasonable
face area velocity (fpm)�
3. The discharge duct must be as short and straight as
possible but of sufcient length to guarantee uniform
airow distribution through the louver for maximum
velocity�
4. In most cases, the cross-sectional “free area” of the
louver must be equal to or larger than the cross-
sectional areas of the intake and/or discharge unit
openings to allow for optimum velocity and reasonable
pressure drop across the louver�
5. Ducts should be insulated if the unit is installed and
operating in cold climates�
6. Adequate access to both the evaporator and condenser
coils as well as the louver must be available for
cleaning purposes�
7. All louver manufacturer instructions, local codes, and
industry accepted guidelines must be followed for all
installations�

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VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
INFORMATION
Discharge air from the condenser air
outlet should be deected away from the
condenser air inlet, to prevent recirculation�
The intake and discharge louver can be in separate frames
or combined in one frame�
The combination intake/discharge louver design (Figure 3)
offers an advantage over separate louvers because it requires
only one wall opening which decreases installation costs�
However, the blades cannot be of uniform conguration (i.e.
the same blade design and angle)� The discharge louver
blades should be angled to direct the airow straight out
horizontally from the unit and the intake blades should be
angled down at approximately 45°�
Figure 3
It is critical that the two air streams be directed in different
directions so that no recirculation of discharge air is allowed to
enter the inlet air stream� In some cases it may be necessary
to provide a deector vane or separator between the two air
streams� If recirculation of the discharge air does occur, the
unit will likely trip on high head pressure and continue to fail
until the louver design is corrected�
Louvers may be manufactured of aluminum (14 gauge) or
steel (18 gauge)� Louver widths of 30 inches or more should
have additional bracing midway along the blades to maintain
proper blade separation� If the louvers are to be installed
in a coastal application or any location with environmental
concerns, then the louvers should be treated�
It is also benecial to angle the bottom of the intake ductwork
up from the louver toward the unit opening to minimize the
possibility of water carryover reaching the unit and allow for
proper drainage Figure 4)�
Louvers should be inspected and cleaned on a regular
basis� A bird screen is required to deter animals and debris
from entering the duct system�
Length of Ductwork for Discharge Air
The VertiCool Classic unit should be located a minimum
distance from the louvered wall to maximize efciency of the
blower� Certain conditions and obstructions at the fan inlet
and outlet adversely affect fan performance (i�e� elbows,
guards, dampers, etc�)� “System Effect” is a term used by the
industry to describe these adverse conditions� It is best to
design the inlet and discharge ductwork to provide minimum
sufcient straight length of duct to reduce system effect and
allow for uniform air discharge�
Figure 5 below illustrates the discharge air velocity prole at
various distances from the centrifugal blower� It is important
to determine the 100% Effective Duct Length to ensure
uniform air discharge�
Combination Intake/Discharge
D
W
“D”
“I”
“D” Discharge“I” Intake
3" Separation Plate
4"
[101�5 mm]
Discharge Louver
Inlet Louver
Access panel for condenser coil cleaning�
Figure 4

Installation, Operation and Maintenance Manual
VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
Based on formulas in ASHRAE Fundamentals – Duct Design,
Chapter 34, the following minimum intake and discharge
100% Effective Duct Lengths (EDL) are recommended:
3 thru 5 tons = 3�5 feet
6 & 8 tons = 4 feet
10 thru 15 tons = 5�5 feet
20 tons = 6�5 feet
25 tons = 8 feet
30 & 35 tons = 8�5 feet
Figure 5
The VertiCool units are supplied with a standard motor
and drive package which provides approximately 0�25”
ESP� Upgrades (optional) are available that can raise this
capability to 1” ESP or more� The drive packages have some
ability to be adjusted in the eld. You must know the overall
duct design in order to determine what drive package will
be required� Normal start-up procedures should be followed
including balancing the system following the completed unit
installation�
Application Data
Voltage 208 / 230 460 575
Variation 187 / 253 414 / 504 518 / 632
Cooling
(Air Entering Evaporator)
DB
(min./max.) 65 / 110
WB
(min./max.) 57 / 72
Water-Cooled
GPM / Ton
(min./max.) 2.5 / 3.5
Leaving Water
(min./max.) 60 / 115
Note: Not all combinations may be valid.
Installation
The VertiCool Classic units can be shipped as a single
package or as a split package which is assembled in the
eld.
Air-Cooled Single Package
1. Move the unit to the desired installation location�
2. Unit contains a full charge of R-410a refrigerant�
3. Install the unit so that controls and access panels are
accessible to the operator and maintenance personnel�
4. Install the condensing section ductwork following the
guidelines and industry accepted practices for the
condenser air inlet and discharge�
5. Install ductwork on the evaporator as required� If the
unit was provided with a discharge plenum having
grilles, no ductwork would be required�
6. Install the condensate trap as outlined below�
7. Wire the unit as outlined below�
Air-Cooled Units Shipped Split or Split In The
Field For Unit Locating
1. Move the unit to the desired installation location�
2. Unit contains a full charge of R-410a refrigerant�
3. Install the unit so that controls and access panels are
accessible to the operator and maintenance personnel�
4. Install the condensing section ductwork following the
guidelines and industry accepted practices for the
condenser air inlet and discharge�
5. When re-assembling the evaporator section to the
condensing section, use a sling or other suitable means
that is sufcient to hold the weight of the section.
Use spreader bars to keep the cabinet from being
deformed�
6. Make sure that the evaporator section is positioned
correctly for the desired air pattern� Care must be
taken when lowering the evaporator section that the
refrigerant resealable ttings are lined up properly and
that they are not damaged in this process� Re-install
the fasteners if removed prior� Systems shipped split
from the factory will have the mounting hardware
located inside the evaporator section�
7. Install ductwork on the evaporator as required� If the
unit was provided with a discharge plenum having
grilles, no ductwork would be required�
8. Install the condensate trap as outlined below�
9. Wire the unit as outlined below�
25%
50%
Outlet Area
Blast Area
Cutoff
Discharge Duct
75%
100% Effective Duct Length

Installation, Operation and Maintenance Manual
VertiCool Classic
9
Subject to change without notice. 20.10-IM (0617)
General Ductwork Recommendations
1. Please make sure that all duct work, evaporator return
and supply air and for air-cooled units the condensing
section inlet and discharge air, is connected to the units
using eld supplied exible duct connectors.
2. Make sure that all duct work is supported
independently from the equipment�
These two installation requirements are meant to minimize
or isolate any unit vibration to help assure that it is not
transmitted into the duct work, to the structure and/or out
into the space�
All ductwork must be designed in accordance with industry
accepted practices� Consult ASHRAE, AMCA or SMACNA
guidelines or standards for details� Use of turning vanes is
recommended�
Verify that the designed duct external static pressure is in
line with the capability of the unit blower / motor provided�
Ducts should be insulated in accordance with applicable
industry standards or per local codes, particularly if the unit
will be operated during cold weather� The condensing unit
intake duct should include a provision to access the inlet
side of the coil for periodic cleaning� It is also best to design
for sufcient clearances for servicing the blower motors,
expansion valves, lters, and any additional accessories
installed�
Plenum Installation
The plenum is typically installed at the factory� However, it
may need to be removed to move the unit into position� The
plenum is held in position with drive screws�
If the plenum has discharge grilles, the grilles will have to
be removed to take the plenum off for re-installation on the
evaporator section�
Condensate Drain Connection
Install a eld fabricated condensate trap and drain line or
a condensate pump as required� Route the condensate
disposal tubing to a suitable location�
Units are equipped with two 3/4” IPS evaporator drain
connections� It is only necessary that one drain connection
be utilized� Make sure that the drain connection not being
used is plugged�
The drain line must be trapped because the coils are
located on the negative side of the blower(s)� The purpose
of the condensate trap is to neutralize the negative pressure
created within the cabinet by the blower�
This negative pressure can vary from less than 1” up to 2”
column. The condensate trap must be of sufcient depth in
water column to permit the condensate to ow from the drain
pan�
The “A” dimension (Figure 6) must equal or exceed the
negative static pressure developed by the supply air blower�
If it does not, the condensate will not drain properly and
may overow the drain pan. The trap must be at least 2-1/2”
deep to maintain a water seal under all operating conditions,
especially during blower start-up�
It is highly recommended that the trap be primed with water
prior to unit start-up�
Each trap must be piped to a suitable waste drain�
Figure 6
Refrigerant Connections
All units are shipped from the factory with a full factory
refrigerant charge. The resealable refrigerant ttings must
be connected and properly tightened to facilitate refrigerant
ow between the evaporator and compressor / condenser
section�
If the unit has been shipped split or has been split to
accomplish installation, the resealable refrigerant ttings
must be connected as follows:
1. On the refrigerant resealable ttings, if not already
accomplished, apply a few drops (5 to 6 droplets are
recommended) of refrigerant oil to the male coupling
halves before starting the assembly (Ref� to Figure 7)�
2. Align each resealable tting and hand thread the
female tting onto the male tting (Ref. to Figure 7).
Continue to hand thread until resistance is observed�
Continued on next page
Unit
“A”
2-1/2"

Installation, Operation and Maintenance Manual
VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
3. Once slight resistance is evident, continue to tighten
the ttings using the appropriate size wrenches listed in
Table 1� Please note that it is important to support the
male side of the tting with a wrench when tightening
the female side with a wrench�
4. If the resealable ttings still feel loose, tighten a bit
more as required�
Figure 7
INFORMATION
Count the number of threaded rotations�
Use Table 1 to determine how many total
rotations are required for proper sealing of
the ttings.
Size Wrench Full Turns Required
3/8" 1-3/16" 6
1/2" 1-3/16" 6
5/8" 1-5/8" 7-3/4
3/4" 1-5/8" 7-3/4
7/8" 1-5/8" 8
1-1/8" 2" 8
INFORMATION
If low refrigerant pressure is evident during
the start-up process, check the tightness
of all resealable ttings. A tting that is not
fully open will restrict refrigerant ow.
Electrical
ELECTRICAL HAZARD
Only a qualied licensed electrician or
other individual that is properly trained in
handling live electrical components should
perform the wiring installation� Failure to
follow all electrical safety precautions and
industry accepted practices when exposed
to live electrical components could result
in death or serious injury�
INFORMATION
Use Copper Conductors Only� Failure
to use copper conductors may result in
equipment damage�
INFORMATION
All electrical wiring must be in accordance
with NEC (National Electrical Code), NFPA
(National Fire Protection Agency) most
current versions as well as any applicable
state or local codes�
INFORMATION
The correct phase sequence of the
incoming power supply is a requirement�
If the phase sequence is not correct it
could cause damage or failure to electrical
components� Reverse the incoming wiring
to resolve the issue� Do not switch any
internal unit wiring�
INFORMATION
Conrm that the incoming power supply
matches the unit data tag�
Female Fitting
Apply oil to male threads Male Fitting
Clockwise Rotation

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VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
INFORMATION
Unit wiring and components have been
designed for the specic unit application
and factory assigned controls� Do not use
the unit transformers or alter the unit wiring
to interface any eld supplied accessories
or controls�
A factory provided power block is installed internal to the
unit’s electrical control panel� Route the main power wires
in accordance with all codes from the disconnect to the unit
power block�
A proper ground termination lug has been provided in the
unit control panel�
ELECTRICAL HAZARD
Conduit is not an acceptable grounding
source� A separate ground conductor must
be connected from Earth Ground to the
factory supplied grounding lug internal to
the unit�
Transformer
Dual voltage units, 208/230, are wired from the factory
for the 208 volt power supply� If the power supply will be
consistently above 220 volts the transformer should be wired
on the 230 volt tap�
Wiring
1. Refer to the wiring diagram that was included with the
unit�
2. Units are completely internally wired at the factory�
3. All units are provided with terminal blocks�
4. Check the unit data tag for the required voltage,
minimum circuit ampacity and maximum fuse size�
5. Route the power wiring through one of the holes
provided in the front corner posts�
6. Power wiring must comply with all National or Local
codes� The power supply must be suitably fused for
wire protection�
7. Use copper conductors only� The unit must be earth
grounded using the ground lug provided in the electrical
box�
8. Select a location to install the thermostat to avoid
vibration, drafts, sun exposure or internal heat sources�
Use an inside wall�
9. Route the correct low voltage wire type and size back
to the unit and through one of the holes provided in the
front corner posts� Connect to the low voltage terminal
block per the wiring diagram supplied�
Wire Size1AWG. Gauge
22 20 19 18 16
40 120 150 190 305
Maximum Wire Length2Feet
Notes:
1. Soilid, Class II copper wire
2. Based on a voltage drop of 1�2 volts per wire�
3. Total wire length is from unit to room thermostat, and
back to unit�
Three Phase Power
On units with three phase power supply, check for proper
blower rotation� If they are running backwards, interchange
two of the incoming power leads�
Do not rewire any components inside the unit�
Electric Heat
On larger units having a high amount of electric heat, a
second power supply may be required� Run the second
power supply to the connections located with the heater�
Follow all National Electrical Codes and Local Codes as
required� Make sure to run a ground wire to the supplied lug�
Route the low voltage wiring for the heater control to the low
voltage terminal block located with the heater�

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Voltage Unbalance
Voltage unbalance occurs when the RMS line voltages on
a 3-phase power supply are unequal� Voltages are never
balanced between phases, but if the level of the unbalance
becomes excessive it will create problems for not only
motors but also controls�
The maximum desirable voltage unbalance is 2�0%�
When testing for voltage unbalance, the phase-to-phase
voltages should be measured rather than the phase-to-
neutral voltages since 3-phase motors are connected across
phases� Use the following formula to determine the percent
of voltage unbalance:
Percent Voltage Unbalance = 100 x (Maximum Voltage
Deviation / Average Voltage)
Example:
Phase-Phase voltages
A-B = 479V
B-C = 472V
C-A = 450V
Average Voltage = (479 + 472 + 450) / 3 = 467
Maximum Voltage Deviation from Average =
467 - 450 = 17 (Must always be positive)
Voltage Unbalance = 100 x (17/467) = 3�6%
In this example the percent of voltage unbalance exceeds the
desired maximum of 2%� Additional checks should be made
at the unit disconnect to conrm the values. Use accepted
industry practices to check or test the quality of the power
supply� Often, it is just a matter of repairing malfunctioning
equipment or redistributing loads to improve the unbalance�
If no cause can be located and resolved for the unit power
supply, the building manager or owner should be notied of
the issue to get the proper power supplied to the unit�
It should be noted that the inclusion of a variable frequency
drive (VFD) with an unbalanced power supply may result in
nuisance tripping and 3rd harmonic currents�
Chilled Water Coil Valves Or
Hot Water Coil Valves
Chilled water or hot water valves, if supplied by United
CoolAir, are typically 2-way� The optional valves are shipped
loose for installation in the eld. The valves are to be mounted
in the outlet line of the coil�
Pressure Switches
High Pressure
This switch shuts the unit down in the event of excessive high
pressure in the discharge line� A manual reset is required at
the high pressure switch�
Low Pressure
This switch shuts the unit down in the event of low pressure
in the suction line� This switch is auto-reset�
Water-Cooled Units
INFORMATION
Do not reduce the water inlet or outlet
connection size as this will restrict water
ow and increase water pressure drop.
CAUTION
Ensure that the water pressure to the unit
does not exceed any valve rating�
INFORMATION
All eld installed piping must conform to
applicable local, state and federal laws�
The following items are to be eld supplied and applied:
A. Water shut-off valves (Gate or Ball Type)
B. Inlet water strainer with isolation shut off valves on
each side for periodic cleaning�
The standard condenser heat exchangers are co-axial type�
These are tube-in-tube type that are chemically cleanable�
The inner tube carries the water and the outer tube the
refrigerant� When designing and installing the water piping,
some consideration for the chemical cleaning should be
made, if desired, for future maintenance�
CAUTION
The condensate drain line should not be
connected to the condenser outlet, as
ooding will occur.

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VertiCool Classic
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INFORMATION
It is advantageous to record the inlet and
water outlet temperatures and the heat
exchanger pressure drop during the unit
start-up procedure� These are then a
valid reference point for maintenance
considerations in the future�
INFORMATION
Field supplied water piping must include
a pet cock or other suitable means at the
highest point to bleed air from the water
piping�
INFORMATION
High inlet water temperature or low water
ow rate may result in nuisance tripping of
the refrigerant high pressure switch�
INFORMATION
Water-cooled units with a glycol cooling
uid will require a higher GPM / Ton ow
rate� Contact the factory for details�
WARNING
Water-cooled units have been designed
for use with fresh water application only�
Do not use for brackish water or salt water
unless appropriate condenser and water
piping has been applied�
INFORMATION
Units have been tested at the factory
before shipment. The test uid at the
factory contains a glycol mixture� It is
important to ush the internal unit piping
and heat exchangers at the job site prior to
start-up or connection to the cooling uid
circuit being used�
Water Piping and Connections
Both the water inlet and outlet of the condensing section
should be equipped with eld supplied shut off valves. This
is needed for shutdown of water supply during long periods
of unit shutdown and/or condenser removal, if required�
If the unit does not have water regulating valves or head
pressure control valves, eld supplied balancing valves may
be required�
INFORMATION
Optional Head Pressure Control Valve(s)
should be incorporated into the unit water
circuit(s) if the cooling uid will be less
than 65° F�
Install and connect a fresh water strainer (eld supplied) to
the water inlet line� Strainer should be readily accessible for
periodic cleaning� Shut off valves on both strainer inlet and
outlet are recommended to facilitate cleaning�
Chilled Water Sections
The chilled water section may be supplied with the lower
section for oor mounting. The chilled water section can also
be supplied as a standalone section�
When being used as a standalone chilled water section, care
must be taken to properly support the section if suspended�
It is advisable to provide a full perimeter frame to assure that
the sheet metal does not buckle�
Provide eld supplied and installed vibration isolation as
required�
Care must be taken when mounting the chilled water section
to assure that adequate service clearance is provided for
access to the components� Make sure that the access
panels can be removed�
The chilled water section will have a control panel�
Dependent upon the system components, this control panel
may be located internal to the evaporator or externally� Wire
high and low voltage to this section as required following
National Electrical Codes or Local Codes�
On larger units having a high amount of electric heat, a
second power supply is required� Run the second power
supply to the connections located with the heater� Follow
all National Electrical Codes and Local Codes as required�
Make sure to run a ground wire to the supplied lug�
Install the chilled water valve per industry accepted practices�

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System Options
Humidier
The optional steam humidier that comes with the unit
functions on the electrode principle. As water lls the plastic
steam generator, it immerses metal electrodes then permits
electrical current ow through the water. This current ow
produces heat which then boils the water into steam� This
steam is then injected on the downstream side of the cooling
coil to provide humidication for the area being served by
the unit� Water is replenished through tubing and the 1/4”
are located on the evaporator section structure. For further
information refer to the Humidier Installation Instruction
which accompanies the unit�
INFORMATION
The humidier should not be subjected
to freezing air conditions� If the unit will
be used for outside air applications an
externally mounted humidier should be
used�
Auxiliary Coils (Hot Water or Steam)
A hot water coil or steam coil when used as heat will be
located in the return air stream between the lters and the
evaporator coil� These are typically installed at the factory�
Some units will include Jack Stands to support the auxiliary
coil / lter box. If the unit is shipped as a single package the
jack stands will be attached� Care should be taken when
moving the unit from the skid to the installation location so
as not to tear or loosen the jack stand where it is attached
to the cabinet�
If the evaporator section is shipped loose the auxiliary coil
section will be attached to the evaporator� The jack stands,
if required, will be placed inside the auxiliary coil section�
The mounting hard- ware will be attached to the jack stand
ange.
If an optional hot water valve is ordered, this will be shipped
loose for installation in the eld.
Control wiring will need to be installed from the hot water
valve back to the unit control panel� Follow all National
Electrical Codes and Local Codes as required�
Any steam valves and other adjunct steam components are
to be eld supplied and installed by others.
Control wiring will need to be installed from the steam valve
back to the unit control panel� Follow all National Electrical
Codes and Local Codes as required�
A pan is included under any hot water coil or steam coil� A
condensate trap will need to be installed for this drain pan� A
trap will need to be installed since this line is in a negative air
stream� Follow the same procedures for this line as for the
unit condensate drain line outlined on page 6�
Pipe the hot water coil or steam coil per industry accepted
practices�
Water Side Economizer (Free Cooling Coil)
A water side economizer coil will be located in the return air
stream between the lters and the evaporator coil. These
are typically installed at the factory�
Some units will include Jack Stands to support the water
side economizer / lter box. If the unit is shipped as a single
package the jack stands will be attached� Care should be
taken when moving the unit from the skid to the installation
location so as not to tear or loosen the jack stand where it is
attached to the cabinet�
If the evaporator section is shipped loose the water side
economizer section may or may not be attached to the
evaporator� The jack stands, if required, will be placed inside
the water side economizer section� The mounting hardware
will be attached to the jack stand ange.
If the unit is shipped as a single package, the water piping
from the unit to water side economizer coil will be factory
installed�
If the water side economizer is shipped as a separate section
or if the unit comes with the evaporator and water side
economizer as a section, the water piping will be shipped
loose for eld attachment.
Air Side Economizer
The air side economizer option is installed on the rear of the
cabinet�
Some units will include Jack Stands to support the air side
economizer / lter box. If the unit is shipped as a single
package the jack stands will be attached� Care should be
taken when moving the unit from the skid to the installation
location so as not to tear or loosen the jack stand where it is
attached to the cabinet�
If the evaporator section is shipped loose the air side
economizer section may or may not be attached to the
Continued on next page

Installation, Operation and Maintenance Manual
VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
evaporator� The jack stands, if required, will be placed inside
the air side economizer section� The mounting hardware will
be attached to the jack stand ange.
The enthalpy sensors for the return air and the outside air
are shipped loose for eld mounting. Follow the instructions
with each sensor for the proper location and mounting�
Field supplied low voltage wiring must be installed between
the two sensors and the terminal blocks located in the unit
control panel� Make sure to use the correct type and wire
gauge size�
When ducting to the air side economizer, exible duct collars
should be utilized to avoid any transmission of vibration into
the duct work�
Split Systems
Systems can be eld modied as a split system option.
Evaporator Mounting
In some situations it is necessary to install the system split�
The evaporator section may be supplied with the lower
section for oor mounting. The evaporator can also be
supplied as a standalone section�
When being used as a standalone evaporator section, care
must be taken to properly support the section if suspended�
It is advisable to provide a full perimeter frame to assure that
the sheet metal does not buckle�
Provide eld supplied and installed vibration isolation as
required�
Care must be taken when mounting the evaporator to assure
that adequate service clearance is provided for access to
the components� Make sure that the access panels can be
removed�
The evaporator section will have a control panel� Dependent
upon the system components this control panel may be
located internal to the evaporator or externally� Wire high
and low voltage to this section as required following National
Electrical Codes or Local Codes�
INFORMATION
Make sure to use the appropriate gauge
of low voltage wire based on the total wire
length so that no more than a 1�2 volt drop
is experienced�
On larger units having a high amount of electric heat, a
second power supply may be required� Run the second
power supply to the connections located with the heater�
Follow all National Electrical Codes and Local Codes as
required� Make sure to run a ground wire to the supplied lug�
Interconnecting Refrigerant Tubing
After the two system sections have been installed, the eld
supplied interconnecting tubing can be run�
(a) Units 10-ton and smaller are provided as standard without
the resealable ttings. In this situation the sections may
be provided with stubbed copper tubing� Follow industry
accepted practices for brazing the eld supplied tubing to the
unit copper tube stubs�
(b) For units supplied with the resealable refrigerant ttings follow
instructions below�
Units are provided with unique self-sealing ttings (Optional
on 10-ton and smaller, standard on 12-ton and larger) on
the refrigerant lines between the sections. These ttings or
couplings allow the two section unit to be separated and
reconnected without loosing the refrigerant charge�
When installed as a split system, an optional interconnect kit
is required for each refrigerant circuit or hot gas bypass line�
If the unit was dened as a split system when ordered, the
ttings will be male on both sections. The interconnect kit will
then consist of the matching female ttings. An interconnect
kit is required for the installer to connect refrigerant lines
between both sections� Refrigerant piping between the
sections is eld supplied.
Systems not ordered from the factory to be installed as a
split system, and that contain resealable ttings, will include
Female Fittings on the evaporator section and Male Fittings
on the condensing section� An optional Interconnect kit(s)
must be ordered indicating that a Male / Female Kit is
required�
The interconnect kit also contains four (4) Schrader ttings.
The installer can place at least one in each refrigerant line or
at one end of the refrigerant line� These enable the refrigerant
line to be evacuated and charged as needed, based on the
size and length�
In some situations, the desired refrigerant line size may
differ from the self-sealing tting size provided. The line size
should be reduced or enlarged at the self-sealing ttings as
necessary�
INFORMATION
On units with more than one refrigerant
circuit, be careful not to intermix liquid,
suction and/or hot gas lines of the various
circuits�

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Subject to change without notice. 20.10-IM (0617)
1. Temporarily hand thread the female halves of the self-
sealing couplings (supplied with the interconnect kit)
onto the male couplings, approximately 1 to 1-1/2 turns�
This is to make sure that the interconnecting tubing will
be routed and brazed with the self-sealing couplings
in their nal proper location, so that there will be no
difculty when the nal coupling assembly is made.
2. If there is a hot gas bypass option, connect that
coupling the same way�
3. Run the interconnecting tubing required� Always follow
accepted industry practices for sizing refrigerant
lines based on line length and elevation differences�
Disconnect the self-sealing couplings that were
temporarily installed in step 1 above�
4. The suction line should be pitched downward to the
compressor, sloping approximately 1/4” every ten feet
to facilitate oil return�
5. “P” traps (eld supplied) are required for all suction
line risers every 15 feet� When the evaporator is above
the condensing section, an inverted “P” trap should be
incorporated as close as possible to the evaporator
(this minimizes ood back / oil slugging during the off
cycle)� If the condensing section is more than 40 feet
above the evaporator, consult the factory for specic
refrigerant components�
INFORMATION
On units with more than one circuit, be
careful not to intermix liquid, suction, and/
or hot gas lines of the various circuits�
INFORMATION
When brazing tubing to the self-sealing
couplings, use a water soaked wet rag,
running water bath or chill blocks on the
quick-connects to prevent overheating the
valves and damaging the seals� Always
apply heat toward the eld installed
refrigerant line� Do not apply heat toward
the coupling valve and seal�
6. Install the Schrader valve ttings into the tubing before
brazing the couplings onto the ends of the tubing� Use
a 1/4" hole to mount the valve� Clean and debur the
tubing before doing any brazing to ensure that no chips
or debris are left in the refrigerant circuit� Remove the
Schrader valve cap and core before doing any brazing�
7. Leak check line sets with nitrogen at 500 psig� After
brazing the tubing to the self-sealing coupling halves,
evacuate each line to 300 microns� Check to make
sure that each line holds a vacuum after removal of the
vacuum pump (indicating no leaks) (micron level should
not go above 500 microns within 10 minutes)� Wipe
off coupling seals and threaded surfaces with a clean
cloth to prevent the inclusion of dirt or foreign material
into the system� Lubricate rubber seal and metal seal in
the male halves with refrigeration oil� Thread coupling
halves together by hand to insure proper mating of
threads� Continue to hand-thread each half-coupling
to its mating half until resistance is felt (approximately
1-1/2 to 1-3/4 turns)� Complete the connection of the
mating half-couplings with a wrench� If the resealable
ttings still feel loose, tighten a bit more as required.
INFORMATION
Count the number of threaded rotations�
Use Table 1 to determine how many total
rotations are required for proper sealing of
the ttings.
Size Wrench Full Turns Required
3/8" 1-3/16" 6
1/2" 1-3/16" 6
5/8" 1-5/8" 7-3/4
3/4" 1-5/8" 7-3/4
7/8" 1-5/8" 8
1-1/8" 2" 8
Table 1 - Resealable Fitting Turns
INFORMATION
If low refrigerant pressure is evident during
the start-up process, check the tightness
of all resealable ttings. A tting that is not
fully open will restrict refrigerant ow.
The drawing below illustrates a typical piping arrangement
for factory ordered split systems
A - Male self-sealing ttings on unit sections
B - Refrigerant piping between sections (eld-supplied)
C - Female self-sealing ttings in interconnect kit (4)
D - Schrader ttings in interconnect kit (4)

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Subject to change without notice. 20.10-IM (0617)
8. Size refrigerant lines per industry accepted practices�
9. Refrigerant piping shall be insulated in accordance with
local codes and / or applicable ASHRAE Standards�
Insulation exposed to weather shall be suitable for
outdoor use� Provide protection from water and
shielding from solar radiation as necessary�
10. Max. total equivalent line length is 100 feet. (a)
Max. elevation difference between Evap. And Cond.
Is 40 feet. (a) (b)
(a) Contact the factory for installations with elevation
differences greater than 40 feet or total equivalent
lengths greater than 100 feet� Alternate line sizes and
specic additional refrigerant circuit components may be
required�
(b) If condensing section is 20 feet or more above the
evaporator an oil separator is to be included for each
circuit�
11. Split must contain refrigerant circuit items as follows:
Equivalent Feet
Oil Separator
Accumulator
Quench Valve
Liquid Line
Solenoid Valve
Discharge Line > 100 X
Ext. Hot Gas Bypass Line > 50 X
Liquid Line Net Down >50 X
Suction Line >100 X X X
Suction Line Ambient > 100° F >50 X X
Suction Line Down > 50 X
12. Add the appropriate charge of R-410a Refrigerant
using the Schrader valves to compensate for the
additional interconnecting tubing as follows:
a. For 3/8” liquid line – add 0�6 oz� per foot
b. For 1/2” liquid line – add 1�2 oz� per foot
c. For 5/8” liquid line – add 1�8 oz� per foot
d. For 7/8” liquid line – add 2�4 oz� per foot
Condensate Pump
If an optional condensate pump is to be used, it will be
mounted external to the unit�
Follow pump manufacturer instructions�
A 115 volt power supply must be eld supplied for the pump.
INFORMATION
The condensate line out of the unit must be
trapped before going into the condensate
pump�
Refer to Figure 8 for the termination of the condensate tubing
inside the pump�
Refer to Figure 9 for the inverted “U” trap that is to be installed
for the condensate line�
Evaporator
Section
Condensing
Section
A
A
A
A
C
C
C
C
B
B
D
D
D
D
Cut tubing at an angle so
that bottom of reservoir
doesn’t close it� Be sure
tubing does not interfere
with oat.
To
Drain
Max� Pump Lift Inverted
“U” Trap
Figure 8
Figure 9

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VertiCool Classic
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Subject to change without notice. 20.10-IM (0617)
Controls
Thermostat
Conrm that the correct thermostat is being applied based
on the number of cooling stages and heating if applicable�
Follow the thermostat manufacturer instructions�
Microprocessor Controller
For units controlled by a microprocessor refer to the specic
instructions for that device�
Flooded Condenser
When the outdoor ambient temperature falls, the condensing
pressure falls� This causes the discharge pressure to fall�
Since the pressure differential across the thermostatic
expansion valve port affects the rate of refrigerant ow, low
discharge pressure generally causes insufcient refrigerant
to be fed to the evaporator. Failure to have sufcient head
pressure will result in low suction pressure and/or iced
evaporator coils�
The purpose of a ooded condenser is to hold back enough
of the condensed liquid refrigerant so that some of the
condenser coil surface is rendered inactive� This reduction
of active condensing surface results in a rise in condensing
pressure and sufcient liquid line pressure for normal system
operation�
The effective range for this option is down to –30° F�
A three–way modulating valve and a receiver tank make up
the ooded condenser refrigerant components.
The valve is placed in the liquid line after the condenser coil�
The receiver is downstream of the valve� The valve limits
the ow of liquid refrigerant from the condenser while at the
same time regulating the ow of discharge gas around the
condenser to the receiver�
During periods of low ambient operation, the receiver
pressure falls until it approaches the setting of the control
point of the valve (typically 295 psig for R-410a)� The valve
then throttles to restrict the ow of liquid from the condenser.
This raises the condenser pressure� Since it is the receiver
pressure that is being maintained, the valve will then start
to throttle open the discharge port when the differential
between the condensing pressure and the receiver pressure
exceeds 20 psi� The hot discharge gas serves to heat up the
cold liquid being passed from the condenser to the receiver�
Thus the liquid reaches the receiver warm and with sufcient
pressure to assure proper expansion valve operation�
The receiver is required to hold all the excess/additional
liquid refrigerant in the system, since the refrigerant will be
returned to the receiver when the high ambient conditions
exist�
In the off-cycle the refrigerant can “migrate” to the condenser,
during periods of low outdoor ambient� On a call for start-
up, the evaporator pressure may not build up to the cut-in
point of the low pressure control� The result may be a failure
of the compressor to start or to short cycle� To eliminate
this potential problem, a time delay is added to bypass the
low pressure switch during start-up to allow the discharge
pressure to build, in turn increasing the suction pressure�

Installation, Operation and Maintenance Manual
VertiCool Classic
19
Subject to change without notice. 20.10-IM (0617)
ELECTRICAL HAZARD
Turn OFF power and lockout service
before conducting any maintenance� Keep
hands, clothing and tools clear of electrical
terminals�
WARNING
Make sure to keep hands and clothing
clear of any moving belts, blowers and
motors while performing any maintenance�
Failure to do so could result in death or
serious bodily injury�
CAUTION
Any maintenance should be conducted
by qualied HVAC service personnel only.
Potentially hazardous situations which
may result in personal injury, equipment or
property damage�
Filters
Do NOT run unit without lters.
Throwaway lters are supplied which are pleated extended
surface type� Filters should be checked monthly for dirt
accumulation and changed when necessary� Replacement
lters must be the same type as originally supplied.
INFORMATION
Unit must be shut off at the disconnect
switch before the lters are serviced. Be
sure to check that the air ow direction
arrows on the lters point in the correct
direction of air ow.
Cleaning The Water-Cooled
Condenser
Any uid that is used to carry the heat away through the
condenser contains, minerals, dust from a cooling tower or
other foreign materials� Over time these contaminants will
build up on the walls of the heat exchanger�
This scale or fouling will result in a reduction in water ow,
less water temperature difference between inlet and outlet,
high condensing temperature and higher uid pressure drop.
All of these affect the operating performance and efciency
of the system and need to be addressed�
Cleaning a water-cooled condenser helps to improve the
heat transfer rate, reduce operational cost, restore efciency,
prolong heat exchanger life and reduce pressure drop
pumping costs� Deposits from water or water treatments,
such as scale, lime, rust or mud are removed�
Each installation is unique. Therefore, the uid quality and
operating conditions will dictate when the heat exchanger
needs to be cleaned�
During the start-up process record the water pressure drop
across the heat exchanger� Also record the inlet and outlet
water temperatures� After a period of time these values can
be checked to see how much loss of operating performance
has occurred� If a 10% or greater change has occurred, it
would be benecial to clean the heat exchanger.
There are a number of commercially available products for
cleaning a heat exchanger� Follow all industry practices to
safely and effectively clean the heat exchanger�
Blowers
Disconnect power and lockout the service before doing any
service or maintenance�
Air-cooled units are provided with adjustable belt drive
blower packages for both the evaporator and condensing
sections� Check that the blower wheel is tight on the shaft
and does not contact the housing� Bearings are permanently
sealed, but should be checked periodically for signs of wear�
Check for restrictions or foreign material in the air circuit�
The drive may be adjusted for different static pressures� If
such an adjustment is made, check that the motor current
draw does not exceed the motor nameplate current by more
than 10%�
Blower Motors
All blower motors are equipped with thermal overload
protectors�
WARNING
Open disconnects to unit before doing
any service or maintenance� A motor that
is off on thermal overload can start any
time when the automatic thermal overload
resets�
Maintenance Procedures

Installation, Operation and Maintenance Manual
VertiCool Classic
20
Subject to change without notice. 20.10-IM (0617)
Blower Speed Adjustment
Blower speed may be changed by adjusting the variable
diameter sheave provided on the blower drive motor�
Sheave may be adjusted by removing the belt and loosening
the setscrew located in the hub of the outer ange. With the
setscrew loosened, the ange may be turned clockwise
to increase blower speed or counter-clockwise to reduce
blower speed�
Typically the motor and drive packages have been sized and
designed for the specic CFM and external static pressure
(ESP) of the application. Before making any changes conrm
what the performance was designed for and what the actual
performance is�
INFORMATION
Setscrew must be positioned directly
above the at section of the threaded
sheave shaft before tightening to hold
adjustment�
INFORMATION
Reduction of airow through excessive
external air friction losses, lowered blower
speed operation with dirty lters, or
obstructed air ow may result in excessive
condensation at air outlets, short cycling,
or total unit shut- down due to evaporator
coil icing�
INFORMATION
Verify that the motor current draw does
not exceed the motor nameplate current
by more than 10%�
Blower Bearing Lubrication
INFORMATION
Unit must be shut off at the disconnect
switch before the blowers are serviced�
Bearings on the smaller units are permanently sealed, but
should be checked periodically for signs of wear�
Larger units have pillow block bearings� Bearings will need
to be lubricated based on the use of the equipment�
Duty Grease Interval
Low Usage 12 Months
Periodic 6 Months
Continuous 1 – 2 Months
Use a high quality lithium grease for blower pillow block
bearings. Wipe off the “Zerk” tting with a rag before adding
grease so as not to introduce dirt into the bearing�
Slowly rotate the shaft while pumping it in� Pump the grease
in slowly so as not to blow out the bearing seal� When the
grease starts to “seep” out of the bearing you have put in
enough new lubricant�
Over lubricating can cause a bearing to fail from overheating
or it can blow out the seal�
Both excessive or inadequate grease may cause premature
failure� Provided there is some grease in the bearings for
lubrication, under lubrication is better than over lubrication
as grease can easily be added but not removed� Always
allow a slight bead around the circumference of the seals to
protect the bearing from foreign matter and helps ush out
the bearing as well�
Wipe off the “Zerk” tting with a rag after adding grease
Belts
Excessive belt tension is the number one cause for blower
bearing failure� Proper belt tension and pulley alignment are
essential for trouble free operation�
Deection is the amount the belt gives when force is applied,
usually by nger, to the belt at the approximate center point
to the belt span�
Insufcient deection indicates that the belt tension is
entirely too tight, and if not loosened somewhat, noise due
to excessive vibration, premature bearing failure, shortened
belt life, and a reduction in supply air blower performance
may result� Tight belts may also overload the motor and
cause the efciency to drop considerably or even premature
motor failure as well�
Excessive deection is an indication that the belt is not tight
enough� If not corrected, slippage may occur causing loss of
blower speed and belt failure� The belts will glaze then crack
or even break due to increased temperatures caused by
slippage� Belts may slip during start-up, but slipping should
stop as soon as the fan reaches full speed�
If the midpoint (midway between the blower and motor shaft)
of the belt is pressed inward, there should be about 1/2” to a
1” of deection when the belt is properly tensioned.