Turboair KUCTB2503 User manual

Turbo air Speeds Up the Pace of Innovation
Part No. KUCTB2503
Refrigeration System
Installation & Operation Manual
Please read this manual completely before attempting to install or operate this equipment !
Unit Cooler
Condensing Unit

2
CONTENTS
Safety Information …………………………………… 3
Inspection ……………………………………………… 3
Locating Unit Cooler ………………………………… 4
Unit Cooler Piping …………………………………… 6
Expansion Valve Selection ………………………… 7
Defrost ………………………………………………… 10
Locating and Mounting Condensing Unit ……… 12
System Operation …………………………………… 13
Unit Cooler Troubleshooting ……………………… 15
System Troubleshooting …………………………… 17
Field Wiring …………………………………………… 19

3
Safety Information
Be sure all power sources are turned off before checking the electric wiring or appliances to avoid electric
shock.
Do not run fan if cover or case is removed. This is to avoid electric shock.
All units are pressurized with dry air or nitrogen gas. All units must be evacuated before charging the
system with refrigerant. Keep finger away from moving parts.
Avoid touching refrigerant lines. Some parts are very hot and can cause burns.
Avoid contacting sharp edges or coil surface that are a potential injury hazard.
Avoid touching the units or electric box in wet hands to prevent electric shock.
Please call the specialized installation company or trained personnel when you installing, moving,
operating of the unit.
Field wiring must confirm to the requirements of units’ electric specification.
Inspection
A person at the job site to receive material holds responsibility. Each shipment should be carefully
inspected against the bill of lading. The shipping receipt should not be signed before careful inspection.
Check carefully for concealed damage. Any shortage or damages should be reported to the delivering
carrier. Damaged material becomes the delivering carrier’s responsibility, and should not be returned to
Turbo air unless prior approval is given. Check the serial tag information with invoice. Report any
discrepancies to Turbo air sales representatives.

4
Locating Unit Cooler.
Minimum space required for Unit Cooler.
Figure 1. One evaporator
H
H
H
Figure 2. Two or more evaporators
H2H
H H
H
H=Space Required, Unit Cooler Height
Recommended location methods of Unit Cooler.
1. Avoid placing Unit Cooler close to doors. Install like Figure 3 or Figure 4.
2. Avoid having them face each other when installing multiple units. Install like Figure 5
3. Recommended placement when installing multiple units see Figure 6.
( H= Sapce Required, Unit Cooler Height )
Figure 3
door
Figure 4
door
Figure 5
door
Figure 6
door
2H
2H
Locate evaporators so that air pattern covers all of the room. Do not restrict the inlet or outlet air

5
stream. When installed, there should be
12”clearance from bottom of the unit. Always
avoid placement of unit coolers directly above
doors and door openings.
Most evaporators can be mounted with rod
hangers, lag screws or bolts. (use 3/8” and 5/8”
stainless steel bolts) Refer to Figure 7. Mount the
unit level so that condensate drains properly.
When using rod hangers, allow adequate space
between the top of the unit and the ceiling. (NSF
Standard 7). The area above the unit cooler must
be sealed or exposed in such away to allow hand
cleaning without the use of tools. When lagging
or bolting unit flush to the ceilings, seal the joint
between the top and the ceiling with an NSF listed
sealant. Ends of open hanger channels must be
sealed to prevent accumulation of foreign material.
Refer to Figures 1 through 4. Air flow distance
must be considered when coolers or freezers will
not accommodate all required evaporators on one
wall. Refer to Figure 7. Traps on low temperature
units must be outside of refrigerated enclosures.
Traps subject to freezing temperatures must be
wrapped with heat tape and insulated.
Figure 7. Unit Cooler Installation Diagram.
BOLTS
LO C KNUTS
NUTS
PIPEHEATER
Unit Cooler Piping.
When brazing refrigerant lines, an inert gas
should be passed through the line at low pressure
to prevent scaling and oxidation inside the tubing.
Dry nitrogen is preferred.
Use only a suitable silver solder alloy on suction
and liquid lines. All piping must be adequately
supported to prevent vibration and breaking.
Tube clamps should have a gasket surface to

6
prevent abrasion.
The system as supplied by Turbo air was
thoroughly cleaned and dehydrated at the factory.
Foreign matter may enter the system by way of
the evaporator to condensing unit piping.
Therefore, care must be used during installation
of the piping to prevent entrance of foreign matter.
Use only refrigeration grade copper tubing
properly sealed against contamination.
Figure 8. Suction piping installation on an
evaporator.
Figure 9. suction piping installation on
multiple evaporators.
Figure 10. Installation of expansion valve bulb.
Refer to Figure 8 through 9. Suction line risers
must be carefully selected, have an oil trap at the
bottom and at 15 foot intervals up the riser. They
should be the same size as the vertical riser
connected to its outlet. Riser should not be larger
in diameter than horizontal runs.
Refer to Figure 10.
Expansion valves are supplied with clamp for
securing bulb to the suction line. The bulb must
be secured at the evaporator outlet, on the side of
a horizontal run of suction line, before any trap.
Do not over tighten bulb clamps or deform the
bulb in anyway. Install all refrigeration system
components in accordance with applicable local
and national codes and in conformance with good
practice required for the proper operation of the
system.
All piping must be protected where it passes
through walls or ceilings. Precautions should be
taken to see that the piping does not touch any
structural the transmission of vibration into the
building.
The piping chase must be thoroughly sealed to
protect the tube and prevent ambient air from
entering the refrigerated space. Seal around the
drain line where it passes through the wall. Air
leaks can cause equipment problems. Damage the
structure and product, increase load, increase

7
operating cast, and can cause a safely hazard. Eliminate all air leaks.
Expansion valve selection.
Expansion valve selection for each model (Table 1)
Table 1 refer to Sporlan and Alco, other expansion valve be referred to their catalogue.
Table 1. Expansion Valve Specs by Model.
MODEL
CAPACITY
(BTUH)
Refrigerant
Evap. Temp
(°F/°C)
EXPANSION VALVE
SPORLAN
ALCO
ADR042
4200
R-404A
25 / -4
SBFSE-A-C
HFESC-1/4-SC
ADR068
6800
SBFSE-A-C
HFESC-1/2-SC
ADR073
7300
SBFSE-A-C
HFESC-1/2-SC
ADR109
10900
SBFSE-A-C
HFESC-1-SC
ADR136
13600
SBFSE-A-C
HFESC-1 1/4-SC
ADR163
16300
SBFSE-B-C
HFESC-1 1/4-SC
ADR196
19600
SBFSE-B-C
HFESC-1 1/2-SC
ADR218
21800
SBFSE-B-C
HFESC-1 1/2-SC
ADR273
27300
SBFSE-C-C
HFESC-2-SC
ADR393
39300
SBFSE-C-C
HFESC-3 1/2-SC
LED042
4200
R-404A
-20 /-29
SBFSE-A-Z
HFESC-1/2-SZ
LED068
6800
SBFSE-A-Z
HFESC-1-SZ
LED082
8200
SBFSE-A-Z
HFESC-1-SZ
LED094
9400
SBFSE-A-Z
HFESC-1-SZ
LED126
12600
SBFSE-B-Z
HFESC-1 1/4-SZ
LED147
14700
SBFSE-B-Z
HFESC-1 1/2-SZ
LED168
16800
SBFSE-B-Z
HFESC-2-SZ
LED189
18900
SBFSE-B-Z
HFESC-2-SZ
LED210
21000
SBFSE-B-Z
HFESC-2-SZ
LED252
25200
SBFSE-B-Z
HFESC-3 1/2-SZ
LED300
30000
SBFSE-B-Z
HFESC-3 1/2-SZ
MODEL
CAPACITY
(BTUH)
Refrigerant
Evap. Temp
(°F/°C)
EXPANSION VALVE
SPORLAN
ADM131
13100
R-404A
25 / -4
SBFSE-A-C
ADM162
16200
SBFSE-A-C

8
ADM248
24800
SSE3C
ADM321
32100
SSE3C
ADM370
37000
SSE4C
ADM480
48000
SSE4C
ADM567
56700
SSE6C
ADM638
63800
SSE6C
MED105
10500
R-404A
-20 /-29
SBFSE-A-Z
MED144
14400
SBFSE-B-Z
MED207
20700
SSE-3-Z
MED275
27500
SSE-4-Z
MED317
31700
SSE-4-Z
MED410
41000
SSE-6-Z
MED513
51300
SSE-7-Z
MED547
54700
SSE-7-Z
MLD103
10300
SBFSE-A-Z
MLD165
16500
SBFSE-B-Z
MLD220
22000
SSE-3-Z
MLD253
25300
SSE-3-Z
MLD332
33200
SSE-4-Z
MLD388
38800
SSE-6-Z
MLD442
44200
SSE-6-Z
TTA056
5600
R-404A
25 / -4
SBFSE-A-C
TTA084
8400
SBFSE-A-C
TTA112
11200
SBFSE-A-C
TTA141
14100
SBFSE-B-C
TTA175
17500
SBFSE-B-C
TTE049
4900
R-404A
-10 /-23
SBFSE-A-Z
TTE074
7400
SBFSE-A-Z
TTE099
9900
SBFSE-A-Z
TTE124
12400
SBFSE-B-Z
TTE138
13800
SBFSE-B-Z
MODEL
CAPACITY
(BTUH)
Refrigerant
Evap. Temp
(°F/°C)
EXPANSION VALVE
SPORLAN
TCA058
5800
R-404A
25 / -4
SBFSE-A-C
TCA087
8700
SBFSE-A-C

9
TCA106
10600
SBFSE-A-C
TCA140
14000
SBFSE-B-C
TCA178
17800
SBFSE-B-C
TCA197
19700
SBFSE-B-C
TCA213
21300
SBFSE-C-C
TCA284
28400
SBFSE-C-C
TCA356
35600
SBFSE-C-C
TCE058
5800
R-404A
25 / -4
SBFSE-A-Z
TCE087
8700
SBFSE-A-Z
TCE106
10600
SBFSE-A-Z
TCE140
14000
SBFSE-B-Z
TCE178
17800
SBFSE-B-Z
TCE197
19700
SBFSE-B-Z
TCE213
21300
SBFSE-B-Z
TCE284
28400
SBFSE-B-Z
TCE356
35600
SBFSE-B-Z
Table 2. Recommended line size for suction diameter. ( R-404A)
SYSTEM
CAPACITY
BTUH
SUCTION TEMPERATURE
+30F
+20F
+10F
-10F
30’
75’
100’
150’
30’
75’
100’
150’
30’
75’
100’
150’
30’
75’
100’
150’
3000
3/8
3/8
1/2
1/2
3/8
1/2
1/2
1/2
1/2
1/2
1/2
5/8
1/2
5/8
5/8
5/8
4000
3/8
3/8
1/2
1/2
1/2
1/2
1/2
5/8
1/2
1/2
5/8
5/8
1/2
5/8
5/8
7/8
6000
1/2
1/2
5/8
5/8
1/2
5/8
5/8
7/8
1/2
5/8
5/8
7/8
5/8
5/8
7/8
7/8
9000
1/2
5/8
7/8
7/8
5/8
7/8
7/8
7/8
5/8
7/8
7/8
7/8
7/8
7/8
7/8
7/8
12000
1/2
5/8
7/8
7/8
5/8
7/8
7/8
7/8
5/8
7/8
7/8
7/8
7/8
7/8
7/8
1 1/8
15000
5/8
5/8
7/8
7/8
5/8
7/8
7/8
7/8
7/8
7/8
7/8
1 1/8
7/8
7/8
1 1/8
1 1/8
18000
5/8
7/8
7/8
7/8
7/8
7/8
7/8
1 1/8
7/8
7/8
1 1/8
1 1/8
7/8
1 1/8
1 1/8
1 1/8
24000
5/8
7/8
7/8
7/8
7/8
7/8
1 1/8
1 1/8
7/8
1 1/8
1 1/8
1 1/8
1 1/8
1 1/8
1 1/8
1 3/8
30000
7/8
7/8
7/8
1 1/8
7/8
1 1/8
1 1/8
1 1/8
1 1/8
1 1/8
1 1/8
1 3/8
1 1/8
1 1/8
1 3/8
1 3/8
36000
7/8
7/8
1 1/8
1 1/8
7/8
1 1/8
1 1/8
1 3/8
1 1/8
1 1/8
1 3/8
1 3/8
1 1/8
1 3/8
1 3/8
1 3/8
42000
7/8
1 1/8
1 1/8
1 3/8
1 1/8
1 1/8
1 3/8
1 3/8
1 1/8
1 3/8
1 3/8
1 3/8
1 3/8
1 3/8
1 3/8
1 5/8
48000
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
54000
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
60000
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
66000
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
1 5/8
SYSTEM
CAPACITY
BTUH
SUCTION TEMPERATURE
-20F
-30F
-40F
LIQUID LINE SIZE
30’
75’
100’
150’
30’
75’
100’
150’
30’
75’
100’
150’
30’
75’
100’
150’

10
3000
1/2
5/8
5/8
5/8
1/2
5/8
5/8
7/8
5/8
5/8
7/8
7/8
3/8
3/8
3/8
3/8
4000
1/2
5/8
5/8
5/8
5/8
5/8
7/8
7/8
5/8
5/8
7/8
7/8
3/8
3/8
3/8
3/8
6000
5/8
7/8
7/8
7/8
5/8
7/8
7/8
7/8
7/8
7/8
1 1/8
1 1/8
3/8
3/8
3/8
3/8
9000
5/8
7/8
7/8
1 1/8
7/8
7/8
7/8
1 1/8
7/8
7/8
1 1/8
1 1/8
3/8
3/8
3/8
3/8
12000
7/8
7/8
1 1/8
1 1/8
7/8
7/8
1 1/8
1 1/8
1 1/8
7/8
1 3/8
1 3/8
3/8
3/8
3/8
3/8
15000
7/8
1 1/8
1 1/8
1 1/8
7/8
1 1/8
1 1/8
1 1/8
1 1/8
1 1/8
1 3/8
1 3/8
3/8
3/8
3/8
1/2
18000
7/8
1 1/8
1 1/8
1 3/8
7/8
1 1/8
1 1/8
1 3/8
1 1/8
1 1/8
1 3/8
1 3/8
3/8
3/8
1/2
1/2
24000
1 1/8
1 1/8
1 1/8
1 3/8
1 1/8
1 1/8
1 3/8
1 3/8
1 1/8
1 1/8
1 5/8
1 5/8
3/8
1/2
1/2
1/2
30000
1 1/8
1 1/8
1 3/8
1 3/8
1 1/8
1 3/8
1 3/8
1 3/8
1 1/8
1 3/8
1 5/8
1 5/8
1/2
1/2
1/2
5/8
36000
1 1/8
1 3/8
1 3/8
1 5/8
1 3/8
1 3/8
1 3/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1/2
1/2
1/2
5/8
42000
1 3/8
1 3/8
1 3/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1/2
1/2
5/8
5/8
48000
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1/2
1/2
5/8
5/8
54000
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1/2
1/2
5/8
5/8
60000
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1/2
1/2
5/8
5/8
66000
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1 3/8
1 3/8
1 5/8
1 5/8
1/2
1/2
5/8
5/8
1. All line size are basic for O.D type L copper tube. The above table is maximum suction size and riser size should
not exceed horizontal size.
2. Suction line size should be selected at pressure drop equivalent to 2F, and reduce estimate of system capacity
accordingly.
3. For easy oil return, use U trap in suction line.
4. Consider double suction risers, if capacity control can reduce capacity 35%below.
DEFROST
Once ice forms in an evaporator coil it keeps building more ice and eventually will lead to equipment
failure if not manually defrosted.
Some symptoms of ice forming in the coil are:
1. loss of air circulation and air throw
2. loss of room temperature.
3. no off-cycle time.
4. flood back.
5. water spitting out of the fans or coil on air defrost systems.
Long term ice formation will crush the refrigerant tubes in the coil causing leaks and major equipment
problems. If ice formation is suspected, carefully check the interior rows of the coil with a good light. Ice
formation usually starts at the bottom of the coil in the middle rows and can be difficult to detect.
For most applications, two to four defrost cycles per day should be adequate. The defrost requirements
will vary on each installation so the defrost settings should be determined by observing the system
operation.
Air defrost
The normal “off cycle” of the compressor may be
adequate to keep the evaporator coil clear of frost.
In other applications, a defrost timer may be
necessary to help assure a clear coil in a medium
temperature environment, “Air defrost” is
initiated by the timer, but the evaporator fans

11
continue to operate to facilitate the melting of
frost on the fan surface. Other types of defrost
schemes require that the fans on the evaporator
shut off during the defrost period.
Electric defrost
The recommended electric defrost circuitry is
typically using a defrost heater.
During defrost cycle, compressor and fan are
stopped automatically by the timer at
predetermined times.
In generally, electric defrost uses defrost timer for
preventing over heating.
There are two kinds defrost timers. Turbo air uses
bimetal method.
During the defrost cycle, if the room temperature
rises above the desired setting, defrost heater will
turn off automatically and if the room temperature
drops lower than desired temperature,
Defrost heater will turn off.
If the defrost time finished, defrost timer will turn
on and the compressor and fans will run
continuously.
At this time, fan power is supplied later than
compressor power by fan delay thermostat. If it
does not, a partial defrost results and the residual
water and slush will re-freeze into ice during the
next cycle. Ice removal will require a manual
defrost.
Defrost Thermostat
Bimetal Disc Type
Turbo air uses Klixon type thermostat made by
Texas Instruments Company.
This thermostat terminates defrost at 50(10)
and prevents the fans from running when the coil
temperature is above 40(4.4). And defrost
termination/fan delay thermostat terminates
defrost at 55(12.8) after defrost is finished.
This will allow fan delay time for eliminating the
residual water and slush in the evaporator coil.
Fan delay time can be eliminated by jumping the
fan switch contacts. This will allow the fans to
start immediately after defrost termination. This
will disable the fan delay.
When the coil temperature reaches approximately
40(1.7), fan delay is sends a signal to the
control circuit, and it will run fan motor. If you
wish to control fan delay time and defrost
termination time, adjust the position of thermostat.
If this method is used, it will result in higher
temperature.
Adjustable Type ( F25 Series )
The F25 Control terminates defrost and delays
evaporator fan operation following a defrost cycle.
The coil temperature rises during the defrost cycle
to the control cut-out setting. At this setting the
defrost cycle terminates and refrigeration starts.
The fan remains off during the initial start-up of
the refrigeration cycle. When the coil temperature
drops to the control cut-in setting, the fan is
turned on. The delayed fan operation prevents
warm moist air from being circulated into the
controlled space and danger of increased vapor
pressure and product damage is eliminated.

12
Defrost Timer Setting
Turbo air uses 8145-20B type timer made by
Paragon company.
Timer should be set correctly. Determine the
number of defrosts per day and the best time of
day for it to occur. Insert pins accordingly. Set the
fail-safe time to terminate the defrost a few
minutes beyond the estimated temperature
termination time. Air defrost termination time is
usually 30 to 50 minutes. The colder the room, the
longer the fail-safe time required. Electric defrost
systems normally have a 25 to 40 minute fail-safe
time.
Head Pressure Control
A. Head Pressure Control Valve System (Standard Models)
The standard valve used on high pressure refrigerant systems controls the head pressure at approximately
180 PSIG.
B. Fan Cycle Pressure Control System (Model “-A”)
Pressure Settings
Evaporator Temp.Range
Fan No
Pressure Switch 1 (PSIG)
Pressure Switch 2 (PSIG)
OFF
ON
OFF
ON
High (40 to 0 °F)
1, 2
157
228
-
-
Extended (30 to -25 °F) & Extra
Low (0 to -40 °F)
1
-
-
100
157
2
157
228
100
157
Locating and Mounting Condensing Unit
Locating Condensing Unit.
Condensing Unit must be located and installed
where there is an unrestricted area. Avoid areas
where there are corrosive vapors or flammable
materials.
Avoid locating units too close to walls. Fan intake
and discharge air space should be at least 1m and
2m from wall. Other sides should be at least 0.5m
from wall. No impediments should be located in
front of condensing units intake and discharge.
If above is not followed correctly noise and
inadequate air flow may result.
Condensing units should be located away from
general public and the street.
Make sure units are kept horizontal.

13
Mounting Condensing Unit.
Mounting base should be concrete or steel
sufficient to support between 2 to 5 times the
weight of condensing unit.
Condensing units must be mounted using
pads to avoid vibration or shifting.
The anchor bolts should be used to fix the unit
and tightened with spring washer and nuts.
Spring Mounted Compressor.
Semi-hermetic compressor unit use the mounting assembly shown in Figure 11, the shipping spacer
is to be in place during shipment to insure maximum support for the compressor body during
transit.
Before the unit is put in operation, the shipping spacer should be removed and discarded.
Before operating the unit, it is necessary to follow these steps.
1. Remove the upper nuts and washers.
2. Remove and discard the shipping spacers.
3. Install the rubber spacer. (rubber spacer tied to compressor.)
4. Replace the upper mounting nuts and washers.
5. Allow 1/16” between the upper nut and the rubber spacer as Figure 11.
Figure 11. Spring Mount.
System Operation.

14
Evaporator Superheat.
Evaporator superheat is generated from the
compressor suction line reducing system
efficiency.
Normally 6 to 12 is acceptable on most
refrigeration systems. Preferably, 6 to 8 on
low temperature systems and 8 to 10 on
medium temperature systems are desired. For
systems operating at higher temperatures, the
superheat can be adjusted to 12 to 15 as
required.
The method of measuring evaporator superheat is
found by P-T method.
Obtain evaporator superheat by measuring the
suction line temperature at the expansion valve
bulb. Obtain pressure at a Schrader fitting in the
evaporator suction connection area, near the
expansion valve bulb, and convert to temperature
with a P-T chart.
Subtract the converted temperature from the
measured temperature and the difference is
superheat at the evaporator. Obtain the desired
superheat by adjusting the expansion valve.
Evaporator superheat greater than 14 can
substantially reduce system capacity, while
superheat less than 4 has the potential for flood
back.
Compressor Superheat.
Compressor superheat has an effect on system
capacity and efficiency. Compressor superheat
affects compressor life and recommends a
minimum of 20 superheat at the compressor.
Too low a compressor superheat can permit liquid
return to the compressor causing damage.
Too high a compressor superheat can cause high
discharge temperature, resulting in lubricant
breakdown, compressor overheating and can lead
to compressor damage or failure.
Compressor superheat can be changed by
adjusting the expansion valve, adding a suction-
liquid line heat exchanger.
Obtain compressor superheat by measuring the
suction line temperature about 6 to 12 inches from
the compressor service valve.
Obtain pressure at the suction service valve and
convert to temperature with a P-T chart. Subtract
the converted temperature from the measured
temperature and the difference is superheat at the
compressor.
Refrigerant Charging.
When charging a system with refrigerant that is in
a vacuum with vacuum pump, the above process
is very important to remove moisture inside
system. The moisture can cause system damage or
failure.
Charge refrigerant into a system through a

15
filter/drier in the charging line. This extra drier
will insure that all refrigerant supplied to the
system is clean and dry. Weigh the refrigerant
drum before charging so an accurate record can
be kept of the weight of refrigerant put in the
system. Liquid refrigerant can be added directly
into the receiver tank and charging 90% of system
refrigerant capacity.
Start the system and finish charging until the sight
glass indicates a full charge and the proper
amount have been weighed in. If the refrigerant
must be added to the system through the suction
side of the compressor, charge in vapor form only.
Liquid charging must be done in the high side
only and with liquid metering devices.
If R-404A is used, liquid must be charged and
read up refrigerant explanatory.
Start-up.
Use the following operating procedure after the installation has been completed,.
1) Check all electrical and refrigerant connections. Check if the electrical status is in manual and if
there are no holes in the refrigerant lines. Start-up
2) Check all fans on the evaporator and condensing unit to be sure they are operational and turning
the proper direction.
3) Check high and low pressure switch, pressure regulating valves, and adjust if necessary.
4) Continue charging until system has sufficient refrigerant for proper operation. Do not
overcharge. Bubbles in a sight glass may be caused by a restriction as well as a shortage of
refrigerant. Check service valve and open if refrigerant is sufficiently charged and you still have
bubbles in the sight glass.
5) Observe system and do not leave unit unattended until the system has reached normal operating
conditions.
WARNING : SCROLL COMPRESSOR IS DIRECTIONAL
DEPENDENT. IF NOISY, SWITCH ANY TWO SUPPLY LINES.
Unit Cooler troubleshooting.
Symptoms
Possible causes
Solution
Cooling is
insufficient. (Room
Insufficient refrigerant
Add refrigerant
Too much oil in unit cooler
Check the easy oil return in suction line.

16
temperature too
high.)
Superheat too high
Adjust expansion valve.
Room thermostat set too high
Adjust thermostat
Coil iced-up
Manually defrost coil. Check defrost
time, period, controls.
Defective distributor
Replace.
Uneven coil
frosting.
Defective distributor
Replace
Defective heater
Replace
Defrost termination set too low
Adjust defrost termination setting higher
and move defrost thermostat.
Ice build up in coil
quickly
Fin spaced too narrow
Replace coil
Evaporating temperature too low
Adjust expansion valve
Decrease of air volume
Check fan and clean air filter
Unit cooler capacity is too small
Replace unit cooler
Fan not operating
Main switch open
Close switch
Blown fuses
Replace fuses. Check for short circuits
or overload conditions
Defective motor
Replace motor
Defective timer or defrost thermostat
Replace defective component
Unit in defrost cycle
Wait for completion of cycle
Coil does not get cold enough to reset
thermostat.
Adjust fan delay setting of thermostat.
Ice accumulating in
drain panel
Defective heater
Replace heater
Drain line plugged
Clean drain line
Defective drain line heater
Replace heater
Defective timer or defrost thermostat
Replace defective component.
Symptoms
Possible causes
Solution
Coil not clearing of
frost during defrost
cycle
Coil temperature not getting above freezing
point during defrost.
Check heater operation
Insufficient defrost period
Adjust timer or more defrost cycle
Defrost cycle too short
Adjust defrost thermostat or timer for
longer cycle
Defective timer or defrost thermostat
Replace defective component
Ice accumulating
on ceiling ,around
Defrost time is too long
Adjust defrost termination thermostat.
Not delaying fans after defrost period.
Check fan delaying thermostat

17
evaporator, on fan
guard, or blades.
Defective defrost thermostat or timer.
Replace defective component
Too many defrosts
Reduce the number of defrosts
System troubleshooting.
symptoms
Possible causes
Solution
Compressor not
running
Main switch open
Close switch
Blown fuse
Check electrical circuits and motor
winding for shorts or grounds.
Replace fuse after fault is corrected.
Loose wiring
Check all wire junctions. Tighten all
terminal screws.
System cable shut down
Replace shutdown cable.
Thermal overload tripped
Overloads are automatically reset.
Check unit when unit come back on
line.
Defective contactor or contactor coil
Replace or repair
System shut down by safety devices.
Check cause of shut down
Liquid line solenoid not open
Repair or replace coil
Noisy
Compressor
Flooding of liquid refrigerant into crankcase
Check expansion valve setting
Improper piping support on suction or liquid
line.
Relocate add hangers.
Worn compressor.
Replace compressor
High discharge
pressure.
Non-condensable in system.
Remove non-condensable.
Too much refrigerant
Remove excess refrigerant
Discharge shut off valve partially closed
Open valve
Fan not running
Check electrical circuit and fuse.
Dirty condenser coil
Clean condenser coil
Low discharge
pressure.
Faulty condenser temperature controls
Check head pressure control
Suction shut off valve partially closed
Open valve
Insufficient refrigerant
Check leaks. Add charge.
Low suction pressure
See corrective steps for low suction
pressure.
symptoms
Possible causes
Solution
High suction
Excessive loads
Reduce load.

18
pressure
Expansion valve overfeeding.
Check bulb location and clamping.
Adjust superheat.
Low suction
pressure.
Lack of refrigerant.
Check for leaks. Add charge.
Evaporator dirty or iced
Clean and defrost.
Clogged liquid line filter drier.
Replace filter drier.
Expansion valve malfunctioning.
Check and reset for proper superheat.
Condensing temperature too low.
Check and replace head pressure control
Improper expansion valve.
Check for proper expansion valve.
Compressor
thermal protector
switch open.
Operating beyond design conditions
Add facilities so that conditions are
within allowable limits.
Discharge valve partially closed
Open valve.
Dirty condenser coil
Clean coil
Overcharged refrigerant
Reduce charge.
Compressor loses
oil
Lack of refrigerant
Check for leaks and add refrigerant
Excessive compression ring blow by.
Replace compressor.
Refrigerant flood back.
Maintain proper superheat at
compressor.
Improper piping or traps.
Correct piping.
Little or no oil
pressure
Clogged suction oil strainer.
Clean.
Excessive liquid in crankcase.
Check crankcase heater.
Adjust expansion valve.
Check the solenoid valve.
Low oil pressure safety switch defective.
Replace.
Oil pump reversing gear stuck in wrong
position.
Reverse direction of compressor
rotation.
Worn bearings.
Replace compressor.
Low oil level.
Add oil.
Loose fitting on oil lines.
Check and tighten system.
Pump housing gasket leaks.
Peplace gasket.
Field Wiring.
Diagram 1. Typical wiring diagram for single evaporator with or without defrost timer.

19
Diagram 2. Typical diagram for single evaporator defrost timer only.
Diagram 3. Typical diagram for single evaporator with defrost timer and single phase heater

20
contactor.
Diagram 4. Typical diagram for single evaporator with defrost timer and 3-phase heater contactor.
Diagram 5. Typical diagram for single evaporator defrost timer only (TTE-TYPE).