McQuay RoofPak RDS 800C Instruction Manual

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Instra

IM 178-6
Group: Applied Systems
Part Number: 347673Y-01
Date: January 1997
Installation & Maintenance Data
RoofPak®Applied Rooftop Systems
Air Handler
RDS 800C & 802C
®
©1997 McQuay International
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Page 2 / IM 178
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Receiving Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Typical Component Locations . . . . . . . . . . . . . . . . . . . 4
Control Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Control Panel Locations . . . . . . . . . . . . . . . . . . . . . . . . 6
Controls, Settings, and Functions . . . . . . . . . . . . . . . . 8
Mechanical Installation. . . . . . . . . . . . . . . . . . . . . . . . . . 10
Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Roof Curb Assembly and Installation . . . . . . . . . . . . . 11
Post and Rail Mounting . . . . . . . . . . . . . . . . . . . . . . . 13
Rigging and Handling . . . . . . . . . . . . . . . . . . . . . . . . . 13
Installing Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Installing Duct Static Pressure Sensor Taps . . . . . . . 15
Installing Building Static Pressure Sensor Taps . . . . 16
Condensate Drain Connection . . . . . . . . . . . . . . . . . . 17
Field Refrigerant Piping and Charging of DX Coils . . 17
Unit Piping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Vestibule Assembly Instructions . . . . . . . . . . . . . . . . 21
Damper Assemblies . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Cabinet Weatherproofing . . . . . . . . . . . . . . . . . . . . . . 25
Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Field Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Field Control Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Preparing Unit For Operation . . . . . . . . . . . . . . . . . . . . . 29
Relief Damper Tie-down . . . . . . . . . . . . . . . . . . . . . . . 29
Spring Isolated Fans . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Adjustment of Scroll Dampers . . . . . . . . . . . . . . . . . . 30
Adjustment of Supply Fan Thrust Restraints . . . . . . . 30
Adjustment of Seismic Restraints . . . . . . . . . . . . . . . 31
Sequences of Operation . . . . . . . . . . . . . . . . . . . . . . . . 32
Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Fan Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
Economizer Operation . . . . . . . . . . . . . . . . . . . . . . . . 32
Cooling Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Heating Operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Legend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Typical Power Circuits With Controls. . . . . . . . . . . . . 35
Table of Contents
Typical Compressor Staging Outputs . . . . . . . . . . . . 35
Typical Main Control Circuit (VAV Units) . . . . . . . . . . 36
Typical Main Control Circuit (CAV-ZTC Units) . . . . . . 37
Typical Main Control Circuit (CAV-DTC Units). . . . . . 38
Typical Actuator Control Circuit . . . . . . . . . . . . . . . . . 39
Typical Supply/Return Fan Control Circuit . . . . . . . . 39
Typical Gas Furnace Control Circuit . . . . . . . . . . . . . 40
(Modulating Burner, Mixed Air Intake)
Typical Electric Heat Control Circuit (Multistage) . . . 41
Unit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Enthalpy Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Phase Voltage Monitor . . . . . . . . . . . . . . . . . . . . . . . . 42
Remote Monitor Panel . . . . . . . . . . . . . . . . . . . . . . . . 42
External Time Clock . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Smoke Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
Mixed Air Temperature Alarm. . . . . . . . . . . . . . . . . . . 43
Duct High Pressure Limit . . . . . . . . . . . . . . . . . . . . . . 43
Variable Inlet Vanes . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Convenience Receptacle/Section Lights . . . . . . . . . . 44
Check, Test and Start Procedures. . . . . . . . . . . . . . . . . 46
Before Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Fan Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
Economizer Start-up. . . . . . . . . . . . . . . . . . . . . . . . . . 47
Cooling System Start-up . . . . . . . . . . . . . . . . . . . . . . 47
Heating System Start-up . . . . . . . . . . . . . . . . . . . . . . 47
Air Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
Final Control Settings . . . . . . . . . . . . . . . . . . . . . . . . . 50
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Preventative Maintenance . . . . . . . . . . . . . . . . . . . . . 55
Unit Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Gas Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Bearing Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . 55
Setscrews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
Supply Fan Wheel-to-Funnel Alignment . . . . . . . . . . 57
Winterizing Winter Coils . . . . . . . . . . . . . . . . . . . . . . . 57
Service and Warranty Procedure . . . . . . . . . . . . . . . . . . 58
In-Warranty Return Material Procedure . . . . . . . . . . . 58
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 58
Product Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
Installation and maintenance are to be performed only by qualified personnel who are familiar with local codes
and regulations, and experienced with this type of equipment. Caution: Sharp edges and coil surfaces are a
potential injury hazard. Avoid contact with them.
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IM 178 / Page 3
Introduction
This manual provides general information about the “C”
vintage McQuay RoofPak applied rooftop unit, Model RDS.
In addition to an overall description of the unit, it includes
mechanical and electrical installation procedures, commis-
sioningprocedures,sequence of operation information,and
maintenance instructions. For further information on the
optional forced draft gas-fired furnace, refer to Bulletin No.
IM 684 or 685.
The MicroTech applied rooftop unit controller is available
on “C” vintage applied rooftop units. For a detailed descrip-
tion of the MicroTech components, input/output configura-
tions, field wiring options and requirements, and service
procedures, refer to Bulletin No. 483, “MicroTech Applied
Rooftop Unit Controller.” For a description of operation and
information on using and programming the MicroTech unit
controller, refer to the appropriate operation manual (see
Table 1).
Table 1. Applied rooftop unit operation manual literature
ROOFTOP UNIT OPERATION MANUAL
CONTROL CONFIGURATION BULLETIN NO.
Variable Air Volume (VAV) OM 108
Constant Air Volume, Zone
Temperature Control (CAV-ZTC) OM 109
Constant Air Volume, Discharge
Temperature Control (CAV-DTC) OM 110
Whentheequipmentisreceived,allitemsshouldbecarefully
checked against the bill of lading to be sure all crates and
cartons have been received. If the unit has become dirty
during shipment (winter road chemicals are of particular
concern),itshouldbecleanedoffwhenreceived.Allunits
should be carefully inspected for damage when received. If
any damage is noticed, the carrier should make the proper
notation on the delivery receipt acknowledging the damage.
The carrier should also fill out a Carrier Inspection Report.
TheMcQuayInternationalTrafficDepartmentshouldthenbe
contacted at [phone].
The unit nameplate should be checked to make sure the
voltage agrees with the power supply available.
Receiving Inspection
RoofPak
Draw-through/Blow-through Coil Section
Cabinet Size
800 = 4,000 to 16,000 cfm
802 = 8,000 to 20,000 cfm
Nomenclature
RDS - 800 C Y E
Heat Medium
A = Natural Gas
E = Electric
F = Fuel Oil
S = Steam
W = Hot Water
Y = None
Cooling Coil Size
L = Large Unit Coil
Y = Contractor Coil or None
Design Vintage
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Page 4 / IM 178
Unit Description
Typical Component Locations
Figure 1 shows a typical RDS unit with the location of the
major components and also lists some major dimensions.
Bottom Return Air
Opening Bottom Discharge
Air Opening
Plan View
94.0
(2388)
Power & Control
Entrances
Outside & Return
Air Dampers
Exhaust
Hood
Main Control
Panel
Discharge Plenum
Cooling Coil
Outside Air
Louvers
Return
Air Fan
Supply Air Fan
Filter Section
Heat Section (Natural Gas,
Oil, Steam, Hot Water,
Electric)
Elevation
Figure 1. Typical component locations
Thesefiguresareforreferenceonly.Seethecertifiedsubmit-
tals for actual specific dimensions.
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IM 178 / Page 5
Control Locations
Figure 2 shows the locations of the various control compo-
nents mounted throughout the unit. See “Control Panel
Locations”forthelocationsofcontrolcomponentsmounted
incontrolpanels. AdditionalinformationisincludedinTable2,
“Controls, Settings, and Functions,” and the wiring diagram
legendwhich is included inthe“Wiring Diagrams” section of
this manual.
Figure 2. Control locations
Return Air
Economizer
Filter
Section
Supply Fan
Section
Blow-through
Heat Section
Blow-through
Coil Section
Discharge Plenum
Section
ACT1
(Optional)
SD2
(Optional)
ACT2
(Optional)
RAT
LT11
(Optional)
S11, REC11
(Optional)
ACT3
PC5 SPS5
OAE
S10, REC10 (Optional)
LT10 (Optional)
HL22 (Optional)
MAT (Optional)
PC7
FS1 (Optional)
VM1 (Optional)
ACT5
(Optional)
SAT
SD1 (Optional)
OAT
VM5 (Optional)
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Page 6 / IM 178
Control Panel Locations
The unit control panels and their locations are shown in the
following figures. These figures show a typical unit configu-
}
F1
S6
S1
PS3
REC1
HS1
KEYPAD DISPLAY
PM
F3
R6
R5
R24
T3
R26
R20
TB6
SPS1
SPS2
NB1
DHL
ADI SB1 OBB
OBA
T1
FB10
FB20
M20 M10
OL20 OL10
FB8
TB8
TB7 DSI
or
PB1
TB10
TB5
NB2
TB1
TB2
TB2
MCB1
T2
Main control panel
Supply Fan
Section
Main Control Panel
Electric Heat Control
Panel (Optional)
ration. Specific unit configurations may differ slightly from
these figures depending on the particular unit options.
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IM 178 / Page 7
Electric heat control panel
TB12
M43 M42 M41
FB43 FB42 FB41
M33 M32 M31
FB33 FB32 FB31
HL4
HL14
T5
SR1
SR2
SR3
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Page 8 / IM 178
Controls, Settings, and Functions
Table 2 presents a listing of all the unit control devices. Included in the table are the device symbol, a description of the device, its function, and any reset information, its location, any device setting, any setting ranges, differentials, and the device part number. Table 2. Controls, settings and functions
SYMBOL DESCRIPTION FUNCTION RESET LOCATION SETTING RANGE DIFFERENTIAL PART NO.
ADI ADI Board Collects and conditions analog and digital inputs. N/A Main control box N/A N/A N/A 658160B-05 DHL Duct high limit Prevents excessive VAV duct pressures; shuts off fan. Auto Main control box 3.5" w.c. (871.8 Pa) 0.05–5.0" w.c. 0.05" w.c. 654938B-01
(12.5–1245.4 Pa) (12.5 Pa), fixed
FS1 Freezestat Shuts off fans, opens heating valve and closes out- Auto Heating section 38°F (3°C) or 35°F–45°F12°F (7°C), fixed 658300B-01
door damper if low air temperature at coil is detected. as required (2°C–7°C)
MAT Mixed air temperature Senses mixed air temperature; sends signal to N/A Inlet of supply fan N/A 3K ohms at N/A 658295B-03
sensor MicroTech controller. 77°F (25°C)
MCB1 Microprocessor Control Processes input information and controls output re- N/A Main control box N/A N/A N/A 654873B-08
Board lays as appropriate.
OAE Enthalpy control Returns outside air dampers to minimum position Auto Economizer section “B” or as required A – D Temperature: 307067D-02
(electromechanical) when enthalpy is too high. 3.5°F (2°C)
Humidity:
5% fixed
Enthalpy control Returns outside air dampers to minimum position Auto Economizer section Fully CW past “D” A – D N/A 492622B-01 (electronic) when outside air enthalpy is higher than return air (when used with
enthalpy (used with RAE). RAE)
OAT Outside air temperature Senses outside air temperature; sends signal to N/A Under condenser N/A 3K ohms at N/A 658295B-02
sensor MicroTech controller. section 77°F (25°C)
OBA, B, C Output Boards Holds MicroTech solid-state output relays. N/A Main control box N/A N/A N/A 665422B-01:
A, B, or C (16-position)
665422B-02:
(8-position)
665422B-03:
(4-position)
PC5, 6 Filter switch Turns on clogged filter light on status panel. Auto Filter sections As required .05–5" w.c. .05" w.c. 654938B-01
(12.5–1245.4 Pa) (12.5 Pa)
PC7 Differential pressure Senses supply fan pressure to prove airflow. Auto Supply fan section .10" w.c. (25 Pa) .05–5" w.c. .05" w.c. 654938B-01
switch (12.5–1245.4 Pa) (12.5 Pa), fixed
RAE Return air enthalpy sensor Used to compare return air enthalpy to outside air N/A Economizer section N/A N/A N/A 492622B-02
enthalpy (used with OAE).
RAT Return air temperature Senses return air temperature; sends signal to Micro- N/A Return air section N/A 3K ohms at N/A 658295B-05
sensor Tech controller. 77°F (25°C)
SAT Supply air temperature Senses discharge air temperature; sends signal to N/A Discharge air section N/A 3K ohms at N/A 658295B-01
sensor. MicroTech controller. 77°F (25°C)
SB1, 2 Staging Board 1 or 2 Provides stepped cooling or heating control. N/A Main control box N/A N/A N/A See IM 483 SD1 Smoke detector, supply air Initiates unit shutdown if smoke is detected. Manual Discharge air section N/A N/A N/A 490250B-01 SD2 Smoke detector, return air Initiates unit shutdown if smoke is detected. Manual Return air section N/A N/A N/A 490250B-01 SPS1 Duct static pressure Converts static pressure signals to voltage signals N/A Main control box N/A 0–5" w.c. N/A 495450B-05
sensor #1 and sends them to MicroTech controller. (0–1245.4 Pa)
1–6 VDC out
SPS2 Duct static pressure Converts static pressure signals to voltage signals N/A Main control box N/A 0–5" w.c. N/A 495450B-05
sensor #2 and sends them to MicroTech controller. (0–1245.4 Pa)
1–6 VDC out
Building static pressure Converts static pressure signals to voltage signals N/A Main control box N/A -0.25–0.25" w.c. N/A 495450B-06 sensor and sends them to MicroTech controller. (-62.3–62.3 Pa)
1–5 VDC out
SPS5 Dirty filter pressure Sensors pressure drop across first filter bank and N/A First filter section N/A 0–5" w.c. N/A 495450B-05
sensor sends signal to MicroTech controller. (0–1245.4 Pa)
1–6 VDC out
Continued on next page
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IM 178 / Page 9
Table 2. Controls, settings and functions (continued)
SYMBOL DESCRIPTION FUNCTION RESET LOCATION SETTING RANGE DIFFERENTIAL PART NO.
SPS6 Dirty filter pressure Sensors pressure drop across final filter bank and N/A Final filter section N/A 0–5" w.c. N/A 495450B-05
sensor sends signal to MicroTech controller. (0–1245.4 Pa)
1–6 VDC out
S1 System switch Shuts off entire control circuit (except crankcase N/A Main control box N/A N/A N/A 013550B-00
heaters).
TD9, 19 Part winding start Reduces inrush amp draw on start-up Auto Main control box 1 sec., fixed N/A N/A 282101D-01
timer (fans)
ZNT1, 2, 3 Space temperature Senses space temperature; sends signal to N/A In building space N/A 3K ohms at N/A See IM 483
sensors MicroTech controller. 77°F (25°C)
GAS HEATING CONTROLS AS Blower air switch Proves presence of combustion air. N/A Gas furnace control 0.4" w.c., fixed N/A N/A 330038B-00
section
FD Flame rod Senses pilot flame. N/A Gas burner assembly N/A N/A N/A 365577A-00 FLC Fan control Closes to energize fan when heat exchanger is warm. Auto Gas heating section Closes at 125°F65°F–220°F25°F (14°C) 340821B-00
(52°C) (18°C–104°C) adjustable
Opens at 100°F50°F–205°F
(28°C) (10°C–96°C)
High limit cutout Opens furnace control circuit on temperature rise. Auto Gas heating section Opens at 200°F 100°F–250°F25°F (14°C),
(93°C) fixed
FSG Flame safeguard Proves pilot flame and controls main gas valve. Manual Gas furnce control N/A N/A N/A See IM 684 or 685
section
GV1 Pilot gas valve Opens to allow flow of gas to pilot burner. Normally Gas heating section N/A N/A N/A 344884B-00
closed
GV2, 3 Main gas valves Open to allow flow of gas to main burner. Normally Gas heating section N/A N/A N/A See IM 684 or 685
closed
HL22 Filter high limit control Opens furnace control circuit on temperature rise. Manual Supply air section Opens at 125°F N/A 25°F (14°C), 479388B-01
(52°C) fixed
HL23 Final filter high limit control Opens furnace control circuit on temperature rise. Manual Final filter section Opens at 165°F N/A 25°F (14°C), 479388B-04
(74°C) fixed
HPR High pressure regulator Regulates pressure to main regulator. N/A In gas line before MPR As specified 10"–13" w.c. N/A See parts catalog
(2491–3238 Pa)
HP5 High gas pressure switch Shuts off burner if pressure goes above set point. Manual Gas heating section 8" w.c. (1993 Pa) 5"–35" w.c. 1"–3" w.c. See parts catalog
(1245–8718 Pa) (249–747 Pa)
LP5 Low gas pressure switch Shuts off burner if pressure goes below set point. Auto Gas heating section 4" w.c. (996 Pa) 3"–21" w.c. 1"–3" w.c. See parts catalog
(747–5231 Pa) (249–747 Pa)
ELECTRIC HEATING CONTROLS HL1, 4 & Secondary heater limit Breaks line voltage to heaters if temperatures are too Manual Electric heat section Cutout=210°F N/A N/A 654962B-01 HL11-14 control high. (99°C)
HL31-34 & Primary heater limit control Breaks control voltage to heat contactor if Auto Electric heat section Cutout=175°F N/A 30°F (16°C) 658245B-01
HL41-44 heater temperatures are too high. (79°C) fixed
Cutin=145°F
(63°C)
HS1 Switch (toggle), Shuts off electric control circuit manually. N/A Main control box N/A N/A N/A 237803D-01
electric heat
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Page 10 / IM 178
Mechanical Installation
Unit Clearances
Service clearance
Allow service clearance approximately as indicated in figure
3 below. Also, it is recommended that a roof walkway be
providedto the rooftop unitand along at leastthe side ofthe
unit that provides access to most controls and serviceable
components.
Figure 3. Service clearance
Legend:
A = Return air section
B = Filter section
C = Coil section
D = Heat section
E = Supply fan section
F = Discharge plenum section
Theinstallationofthisequipmentshallbeinaccordancewith
the regulations of authorities having jurisdiction and all
applicable codes. It is the responsibility of the installer to
determine and follow the applicable codes. Sharpedgesareinherenttosheetmetalparts,screws,
clips, and similar items. Can cause personal injury.
Thisequipmentistobeinstalledandoperatedonlybyan
experienced installation company and fully trained per-
sonnel.
Exercise caution when servicing equipment.
ABE
60"
(1524 mm)
90"
(2286 mm)
60"
(1524 mm)
60"
(1524 mm)
To Roof
Access
Location
Roof
Walkway Varies With Unit Arrangement
Refer to Certified Drawing & Note
D D C F
C
!
CAUTION
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IM 178 / Page 11
Ventilation clearance
Following are minimum ventilation clearance recommenda-
tions. The system designer must consider each application
and assure adequate ventilation. If this is not done, the unit
will not perform properly.
Unit(s) surrounded by a screen or a fence:
1. The bottom of the screen or fence should be at least 1 ft.
(305 mm) above the roof surface.
2. The distance between the unit and the screen or fence
should be as described in “Service clearance.”
3. The distance between any two units within the screen or
fence should be at least 120" (3048 mm).
Unit(s) surrounded by solid walls:
1. If there are walls on one or two adjacent sides of the unit,
thewallsmaybeanyheight.Iftherearewallsonmorethan
two adjacent sides of the unit, the walls should not be
higher than the unit.
2. The distance between the unit and the wall should be at
least 96" (2438 mm) on all sides of the unit.
3. The distance between any two units within the walls
should be at least 120" (3048 mm).
Do not locate outside air intakes near exhaust vents or
other sources of contaminated air.
If the unit is installed where windy conditions are com-
mon, wind screens should be installed around the unit,
maintaining the clearances specified above. This is particu-
larly important to prevent blowing snow from entering out-
side air intakes.
Overhead clearance
1. Unit(s)surrounded by screens orsolidwalls shall have no
overhead obstructions over any part of the unit.
2. The following restrictions shall be observed for overhead
obstructions above the air handler section (see Figure 4):
a. There shall be no overhead obstructions above the
furnace flue, or within 9" (229 mm) of the flue box.
b. Overheadobstructionsshallbenolessthan2"(51mm)
above the top of the unit.
c. There shall be no overhead obstructions in the areas
above the outside air and exhaust dampers that are
farther than 24" (610 mm) from the side of the unit.
Figure 4. Overhead clearance
24"
(610 mm)
Max.
2" (51 mm) Min.
Top of Unit
To Overhead
Obstruction
24"
(610 mm)
Max.
Overhead
Canopy
Flue Box
9" (229 mm)
Min. To Flue Box
Typical All Sides
Theroofcurbandunitmustbelocatedonaportionoftheroof
that can support the weight of the unit. The unit must be
supported to prevent bending or twisting of the machine.
If building construction could allow the transmission of
sound and vibration into the occupied space, it is recom-
mended that the unit be located over a noncritical area. It is
the responsibility of the system designer to make adequate
provisions for noise and vibration in the occupied space.
The curb and unit must be installed level to allow the
condensate drain to flow properly.
Integral supply and return air duct flanges are provided
with the RDS roof curb, allowing connection of ductwork to
the curb before the unit is set. The gasketed top surface of
the duct flanges seals against the unit when it is set on
the curb. It is not recommended that these flanges support
the total weight of the ductwork. Refer to the “Installing
ductwork” section for details on duct connections. It is
criticalthatthecondensatedrainsideoftheunitbenohigher
than the opposite side.
Assembly of a typical RDS roof curb is shown in Figures
5a and 5b. Parts A through H are common to all units having
bottomreturnopenings.Dependingontheunit length, Parts
L and M may be included with the roof curb kit to create the
correct overall curb length.
Roof Curb Assembly and Installation
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Page 12 / IM 178
Assembly instructions
1. SetcurbingpartsAthroughHperdimensionsshownover
roof opening or on a level surface. Note location of return
and supply air openings.
2. Ifapplicable,setothercurbingparts(D,L,M,etc.)inplace
makingsurethattheorientationagreeswiththeassembly
instructions.Checkalignmentofallmatingboltholes.See
Detail “A”.
3. Bolt curbing parts together using fasteners provided.
Tighten all bolts finger tight.
4. Square entire curbing assembly and securely tighten all
bolts.
5. Positioncurbassemblyoverroofopenings.Curbmustbe
level from side to side and over its length. Check that top
surface of the curb is flat with no bowing or sagging.
6. Weld curbing in place. Caulk all seams watertight. Remove
backing from 0.25" (6 mm) thick x 1.50" (38 mm) wide
gasketing and apply to surfaces shown by crosshatching.
7. Flash curbing into roof as shown in Detail “B”.
8. PartsEandFarenotrequiredonunitswithnoreturnshaft
within the curb perimeter.
9. Parts G and H are not required on units with no supply
shaft within the curb perimeter.
38.8
(984)
7.5
(191)
2
(51)
“X”
Inside
“YY”
1.5
(38)
76 (1930)
Inside
6.8
(173)
20
(508)
Inside
85
(2159)
“Y”
Inside
“XX”
62.8
(1594)
See Detail “A”
Supply
Air
Return
Air
Figure 5b. RDS roof curb assembly instructions
Main unit curb
➀Unit base
➁Curb gasketing
➂2 x 4 nailer strip
√Galvanized curb
➄Cant strip
(not furnished)
≈Roofing material
(not furnished)
∆Rigid insulation
not furnished)
➇Counterflashing
(not furnished)
➈Flashing
(not furnished) Equal Length
Side Supports
Detail “A”
Using remaining side supports in this area,
align lengths on opposite sides of assembly
and install a cross support “D” at each splice.
RETURN “X” “Y” “XX” “YY”
FAN IN. MM IN. MM IN. MM IN. MM
NONE 24.0 610 82.0 2083 6.8 173 1.5 38
(2) 15" FC 24.0 610 82.0 2083 6.8 173 1.5 38
30" AF 30.0 762 76.0 1930 6.8 173 4.5 114
40" AF 36.0 914 78.0 1981 14.8 376 3.5 89
Figure 5a. RDS roof curb assembly instructions
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IM 178 / Page 13
Post and Rail Mounting
When mounting by post and rail, the structural support
should be run the full length of the unit. The structural
member should be located at the base of the unit as shown
inFigure6assuringthe shaded area is wellsupportedbythe
structural member.
To assure proper system operation, it is important
that the unit is mounted level.
The post and rail setup should be done so that the unit
is level from side to side and over its entire length.
Ifresilient material is placedbetween the unit andthe rail,
insert a heavy steel plate between the unit and the resilient
material to distribute the load. Cabinet penetrations (electri-
cal, piping, etc.) should be sealed in a professional manner
to protect against moisture and weather.
Figure 6. Post and rail mounting
Rigging and Handling Instructions
Unit has either four or six lifting points (four-point shown below).
Caution: All lifting points must be used.
Note: Rigging cables must be at least as long as distance “A”.
Lift Only As Indicated
*Maximum recommended width for structural member is 5" (127 mm) to
allow for adequate space for duct connections and electrical entry.
Rigging and Handling
Liftingbracketswith 2" (51 mm) diameterholesare provided
on the sides of the unit.
Use spreader bars, 96" to 100" (2438 to 2540 mm) wide
to prevent damage to the unit cabinet. Avoid twisting or
uneven lifting of the unit. The cable length from the bracket
to the hook should always be longer than the distance
between the outer lifting points.
If the unit must be stored at the construction site for an
intermediateperiod,settheunitinareasonablylevelposition
with adequate support.
Figure7showsanexampleof therigginginstructionlabel
shipped with each unit.
All lifting points must be used. Adjustment may be re-
quired for the middle cable in a 6-cable arrangement.
Figure 7. Rigging and handling instruction label
94"
(2388 mm)
*5"
(127 mm)
Caution: Lifting points may not
be symmetrical to center of
gravity of unit. Ballast or un-
equal cable lengths may be re-
quired.
A
Spreader Bars
Required
!
CAUTION
!
CAUTION
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Page 14 / IM 178
Lifting points
To determine the required lifting cable lengths and whether
four-orsix-pointliftingisrequired,useTables3and4below
and Figure 8.
Referring to Figure 8, note that dimension A is the dis-
tance between the outer lifting points. The four outer rigging
cables must be equal to or longer than dimension A. Dimen-
sion B shows the minimum distance between the outer and
theinnerliftingpointsforsix-pointlifting.Thiscanbeusedto
roughly determine the required length of the middle cables
for six-point lifting. Dimension A can be determined by
subtracting dimensions X and Y from dimension Z (i.e., A =
Z – X – Y).
Where:
Z = Total unit length in inches (refer to certified drawings for
this dimension).
X = Outdoor/returnairsectionlength(refertoTable3forthis
dimension).
If A ≤288" (7315 mm), 4-point lifting is sufficient.
If A >288" (7315 mm), 6-point lifting is required.
Table 3. “X” dimension (see Figure 8)
OUTDOOR/RETURN AIR
SECTION 800C 802C
100 O.A. 00
PLENUM 40" (1016 mm) 52" (1321 mm)
0-30% O.A. 40" (1016 mm) 52" (1321 mm)
0-100% ECONOMIZER 40" (1016 mm) 52" (1321 mm)
0-100% ECONOMIZER
WITH 15" RETURN FAN 62" (1575 mm) —
0-100% ECONOMIZER
WITH 30" RETURN FAN 52" (1321 mm) 52" (1321 mm)
0-100% ECONOMIZER
WITH 40" RETURN FAN — 80" (2032 mm)
Y=0 Y=0
Figure 8. Unit type RDS
4 lifting points 6 lifting points
800C: B Min. = 62" (1575 mm)
802C: B Min. = 84" (2134 mm)
A
Z
X
B
A
Z
X
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IM 178 / Page 15
Installing Ductwork
For bottom discharge and return units not provided with a
McQuay roof curb, the installing contractor should make an
airtight connection by attaching field fabricated duct collars
to the bottom surface of either the roof curb’s duct flange or
theunit’sductopening.Donotsupportthetotalweightofthe
ductwork fromhe unit or these flanges. Refer to Figure 9.
Units with optional back return, side discharge, or front
dischargeallhaveductcollarsprovided.Forbackreturnand
frontdischargeopenings,the collars are exposedbyremov-
ing unit shipping covers. For side discharge units, the duct
collar is exposed by removing the plenum section access
door and door gasketing.
Flexibleconnectionsshouldbeusedbetweentheunitand
ductwork to avoid transmission of any potential vibration
from the unit to the structure.
DuctworkshouldbedesignedperASHRAEandSMACNA
recommendationstominimizelossesandsoundtransmission.
Where return air ducts are not required, it is recommended
that a sound absorbing T or L section be connected to the
unit return to reduce noise transmission to the occupied
space.
Ductwork exposed to outdoor conditions must be built in
accordance with ASHRAE and SMACNA recommendations
and local building codes.
NOTICE
Onunitswithsidedischarge,accesstoplenummounted
components becomes difficult once ductwork is in-
stalled.
Installer must provide access in the ductwork for plenum
mounted controls.
Figure 9. Installing ductwork
Installing Duct Static Pressure Sensor Taps
For all VAV units, duct static pressure taps must be field
installed and connected to the pressure sensors in the unit.
SensorSPS1isstandard;additionalsensorSPS2isoptional.
Thesesensorsarelocatedatthebackoftheunit’sdischarge
plenum (see “Control Panel Locations” in the “Unit Descrip-
tion” section of this manual).
The duct static pressure sensing tap must be carefully
locatedand installed. Improper location or installation ofthe
sensing tap will cause unsatisfactory operation of the entire
variableair volume system. Following are pressure taploca-
tionandinstallationrecommendations.Theinstallationmust
comply with local code requirements.
Fragile sensor fittings. May damage pressure sensor.
If tubing must be removed from a pressure sensor fitting,
use care. Do not wrench the tubing back and forth to
remove or the fitting may break off.
1. Installatee fitting with a leak-tightremovablecap in each
tube near the sensor. This will facilitate connecting a
manometer or pressure gauge if testing is required.
2. Usedifferentcoloredtubingfortheductpressure(HI)and
reference pressure (LO) taps, or tag the tubes.
3. Locate the duct pressure (HI) tap near the end of a long
duct to ensure that all terminal box takeoffs along the run
will have adequate static pressure.
4. Locatetheducttapinanonturbulentflowareaoftheduct.
Keep it several duct diameters away from takeoff points,
bends, neckdowns, attenuators, vanes, or other irregu-
larities.
5. Use a static pressure top (Dwyer A302 or equivalent) or
the bare end of the plastic tubing for the duct tap. (If the
duct is lined inside, use a static pressure tip device.)
6. Install the duct tap so that it senses only static pressure
(not velocity pressure). If a bare tube end is used it must
be smooth, square (not cut an angle), and perpendicular
to the airstream (see Figure 10).
7. Locate the reference pressure (LO) tap somewhere near
the duct pressure tap within the building (see Figure 10).
If the reference tap is not connected to the sensor,
unsatisfactory operation will result.
8. Route the sensing tubes to the sensor(s) mounted on the
9.8
(249)
4.6
(117)
Unit Duct
Opening
Unit Base
Flexible
Connector Roof Curb
Duct Flange
in Roof Curb
Ductwork
!
CAUTION
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Page 16 / IM 178
backwall of the discharge plenum. Sensing tubesshould
enter the unit discharge plenum through the main supply
duct trunk. Make sure that duct penetrations are sealed
and that tubing is protected by rubber grommets. Care-
fully connect the HI and LO tubes to the appropriate
sensor fittings.
Figure 10. Duct static pressure tap installation Figure 11. Static pressure tubing entrance locations
Installing Building Static Pressure Sensor Taps
Ifa unit has directbuildingstatic pressure control capability,
staticpressuretapsmustbefieldinstalled and connected to
pressure sensor SPS2 in the unit. This sensor is located at
the back of the discharge section (see “Control Panel Loca-
tions” in the “Unit Description” section of this manual).
The two static pressure sensing taps must be carefully
locatedand installed. Improper location or installation ofthe
sensing taps will cause unsatisfactory operation. Following
are pressure tap location and installation recommendations
forbothbuildingenvelopeandlab,or“spacewithinaspace,”
pressure control applications. The installation must comply
with local code requirements.
Fragile sensor fittings. May damage pressure sensor.
If tubing must be removed from a pressure sensor fitting,
use care. Do not wrench the tubing back and forth to
remove or the fitting may break off.
Building pressurization applications
1. Installatee fitting with a leak-tightremovablecap in each
tube near the sensor. This will facilitate connecting a
manometer or pressure gauge if testing is required.
2. Locate the duct pressure (HI) tap in the area that requires
the closest control. Typically, this is a ground level floor
that has doors to the outside.
3. Locate the building tap so that it is not influenced by any
source of moving air (velocity pressure). These sources
may include air diffusers or outside doors.
4. Route the building tap tube to sensor SPS2 mounted on
the back wall of the discharge plenum. Sensing tube
should enter the unit discharge plenum through the main
supply duct trunk. Make sure that duct penetration is
sealedand that tubingis protected bya rubber grommet.
Carefully connect to the HI sensor fitting.
5. Locate the reference pressure (LO) tap on the roof. Keep
it away from the condenser fans, walls, or anything else
that may cause turbulence. Mount it high enough above
the roof so that it is not affected by snow. If the reference
tap is not connected to the sensor, unsatisfactory opera-
tion will result.
6. Useanoutdoorstaticpressuretip(DwyerA306orequiva-
lent) to minimize the adverse effects of wind. Place some
type of screen over the sensor to keep out insects.
Loosely packed cotton works well.
7. Route the outdoor tap tube to sensor SPS2 mounted on
the back wall of the discharge plenum. Sensing tube
shouldentertheunitdischargeplenumthroughaholecut
in the back wall of the discharge plenum. Make sure that
the penetration is sealed and that tubing is protected by a
rubber grommet. Carefully connect to the LO sensor fitting.
Lab pressurization applications
1. Installatee fitting with a leak-tightremovablecap in each
tube near the sensor. This will facilitate connecting a
manometer or pressure gauge if testing is required.
2. Use different colored tubing for the controlled space
pressure (HI) and reference pressure (LO) taps, or tag the
tubes.
3. Regardless of whether the controlled space is positive or
negative with respect to its reference, locate the HI
pressuretapinthecontrolledspace.(Thesetpointcanbe
set between –0.2" and 0.2" w.c.)
4. Locate the reference pressure (LO) tap in the area sur-
rounding the controlled space. If the reference tap is not
connected to the sensor, unsatisfactory operation will
result.
5. Locate both taps so that they are not influenced by any
source of moving air (velocity pressure). These sources
may include air diffusers or doors between the high and
low pressure area.
6. Route the tap tubes between the curb and the supply
duct, and feed them into the unit through the knockout in
the bottom of the control panel (see Figure 11).
7. Connectthetubestotheappropriate1⁄4"fittingsonsensor
SPS2.Assurethatthesensordoesnotsupporttheweight
of the tubing; use tube clamps or some other means.
To Sensor
“HI” Input
Pressure Sensing
Tubing
To Sensor
“LO” Input
Tube Clamps
Tubing Extends
Thru Approx.
1/8"
Rubber
Grommet
Outdoor Static
Pressure Tubing
Entrance (Field
Cut)
Main Control
Panel
Indoor Static
Pressure Tubing
Entrance
Control Wiring
Raceway Cover
!
CAUTION
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IM 178 / Page 17
The unit is provided with a 1.5" male NPT condensate drain
connection.Refertocertifieddrawingsfortheexactlocation.
Theunitanddrainpanmustbelevelsidetosideanda P-trap
must be installed for proper drainage.
RDS units may have positive or negative pressure sec-
tions. It is recommended that traps be used in both cases
with care given to negative pressure sections. In Figure 12,
dimension A should be a minimum of 8" (203 mm). As a
conservative measure to prevent the cabinet static pressure
fromblowingordrawingthewateroutofthetrapandcausing
air leakage, dimension A should be two times the maximum
staticpressureencounteredinthecoilsectionininchesw.c.
Drainage of condensate directly onto the roof may be
acceptable; refer to local codes. It is recommended that a
small drip pad of either stone, mortar, wood or metal be
provided to protect the roof against possible damage.
If condensate is to be piped into the building drainage
system, the drain line should be pitched away from the unit
ataminimumof1⁄8"perfoot.Thedrainlinemustpenetratethe
roof external to the unit. Refer to local codes for additional
Condensate Drain Connection
requirements. Sealed drain lines require venting to assure
proper condensate flow.
Where the cooling coils have intermediate condensate
pans on the face of the evaporator coil, copper tubes near
bothends of the coil providedrainage to the main drainpan.
Checkthatthecoppertubesareinplaceandopenbeforethe
unit is put into operation.
Because drain pans in any air conditioning unit will have
somemoisture in them, algae,etc. will grow. Periodicclean-
ing is necessary to prevent this buildup from plugging the
drain and causing the drain pan to overflow. Also, the drain
pans should be kept clean to prevent the spread of disease.
Cleaning should be performed by qualified personnel.
Biological hazard. May cause disease.
Cleaning should be performed by qualified personnel.
Figure 12. Condensate drain connection
}
4" (102 mm)
Minimum
Minimize This
Dimension
Note: Drain line
must not
be run higher
than this level.
“A”
[8" (203 mm) Min.
or 2 x “P”] Copper Tube
(one each end of coil)
See View “A”
View A
Drain Pan
Static Pressure “P”
(in. w.c.)
RDSunitsthatshipfromthefactorywithDXcoilsinstalleddo
notinclude refrigerant piping orrefrigerantcontrols. The coil
assembly is ready for field connections at the distributors
and at the suction headers. Piping kits that provide the
necessaryliquidandhotgaspipingandcontrolcomponents
are available for field installation.
Field installed refrigerant piping may exit the unit cabinet
at one of the following locations:
1. Through the floor of the unit.
2. Through the discharge and bulkhead of the unit.
3. Through a cabinet door near the DX coil that is not
required for service areas.
Caution:Foranyoftheabove cabinetpenetrations,thehole
must be tightly sealed to prevent water or air leakage.
In preparing for field piping, the plastic plugs on the
distributor must be removed and the copper caps at the
suction header connections must be unsweated.
Piping design, sizing and installation information pre-
sented in the “ASHRAE Handbooks” should be followed in
the design and installation of interconnecting piping. The
RDSandcondensingunitsareintendedtobesetatthesame
elevation as close as possible to each other to minimize
Field Refrigerant Piping and Charging of DX Coils
The pounds of refrigerant in the system may exceed the
capacity of the condenser, depending on the amount of
refrigerant in the liquid lines between the DX coil and the
condensing unit. Refer to condenser manufacturer for
information about refrigerant capacity. Suitable means of
containing the refrigerant is required.
refrigerant pressure drop. The piping must be designed and
installed to prevent liquid refrigerant carryover to the com-
pressor and to assure a continuous return of compressor oil
from the system.
On systems with optional hot gas bypass, it is important
thatthebypasssolenoidvalvebelocated atthecondens-
ing unit and not at the DX coil to prevent liquid return and
damage to the compressor.
!
WARNING
!
CAUTION
!
WARNING
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Page 18 / IM 178
Piping recommendations
1. Use type K or L clean copper tubing. All joints should be
thoroughly cleaned or brazed with high temperature solder.
2. Piping sizes should be based on temperature/pressure
limitations as recommended in the following paragraphs.
Undernocircumstancesshouldpipesizebebasedstrictly
upon coil or condensing unit piping connection size.
3. Suction line piping pressure drop should not exceed the
pressure equivalent of 2°F (1°C), 3 psi (20.7 kPa) per 100
feet (30.5 m) of equivalent pipe length. After the suction
line size has been determined, the vertical suction risers
should be checked to verify that oil will be carried up the
riser and back to the compressor. The suction line(s)
should be pitched in the direction of refrigerant flow and
adequately supported. Lines should be free draining and
fullyinsulatedbetweentheevaporatorandthecompressor.
4. Verticalsuctionrisersshouldbechecked usingTable4to
determine the minimum tonnage required to carry oil up
suction risers of various sizes.
5. The liquid line should be sized for a pressure drop not to
exceed the pressure equivalent of 2°F (1°C), 6 psi (41.4
kPa) saturated temperature. The RDS unit includes a
factoryinstalledfilter-drier,solenoidvalve,andsightglass
in each liquid line, upstream of the thermostatic expan-
sion valve.
Table 4. Minimum tonnage (R-22) to carry oil up suction
riser at 40
° F saturated suction
LINE SIZE
O.D. 11⁄8"1
3
⁄8"1
5
⁄8"2
1
⁄8"2
5
⁄8"3
1
⁄8"3
5
⁄8"4
1
⁄8"
MINIMUM
TONS 1.50 2.50 3.80 7.60 13.10 20.4 29.7 41.3
Note: When compressor minimum tonnage is less than shown in the above
table for a given line size, double suction risers will be required.
Leak testing
The field piping system should be checked for leaks prior to
charging. Leak testing must be performed to current EPA
standards and regulations. After making any necessary re-
pair, the system should be evacuated as described in the
following paragraphs.
Do not use oxygen to build up pressure.
A serious explosion could result from using oxygen to
build up pressure, resulting in severe personal injury or
death.
Evacuation
Afterithasbeendeterminedthattheunitistightandthereare
no refrigerant leaks, the system should be evacuated. The
use of a vacuum pump with a pumping capacity of approxi-
mately 3 cu.ft./min. and the ability to reduce the vacuum in
the unit to at least 1 millimeter (1000 microns) is recom-
mended.
1. A mercury manometer or an electronic or other type of
micron gauge should be connected to the unit at a point
remote from the vacuum pump. For readings below 1
millimeter, an electronic or other micron gauge should be
used.
2. The triple evacuation method is recommended and is
particularlyhelpfulifthevacuumpumpisunabletoobtain
the desired 1 millimeter of vacuum. The system is first
evacuated to approximately 29" (740 mm) of mercury.
Enough refrigerant vapor is then added to the system to
bring the pressure up to 0 pounds (0 microns).
3. Thenthesystemisonceagainevacuatedto29"(740mm)
of vacuum. This procedure is repeated three times. This
methodcanbemosteffectivebyholdingsystempressure
at0pounds (0 microns) for aminimumof 1 hour between
evacuations.Thefirstpulldownwillremoveabout90%of
the noncondensables, the second about 90% of that
remainingfromthefirstpulldown,afterthethird,only1/10
of 1% of noncondensables will remain.
Table 5 below shows the relationship between pressure,
microns, atmospheres, and the boiling point of water.
Table 5. Pressure-vacuum equivalents
ABSOLUTE PRESSURE ABOVE ZERO VACUUM BELOW 1 ATMOSPHERE APPROXIMATE BOILING POINT
MERCURY MERCURY FRACTION OF OF H2O AT EACH
MICRONS PSIA (MM) (IN.) 1 ATMOSPHERE PRESSURE (°F)
0 0 760.00 29.921 — —
50 0.001 759.95 29.920 1/15,200 –50
100 0.002 759.90 29.920 1/7,600 –40
150 0.003 759.85 29.920 1/5,100 –33
200 0.004 759.80 29.910 1/3,800 –28
300 0.006 759.70 29.910 1/2,500 –21
500 0.009 759.50 29.900 1/1,520 –12
1,000 0.019 759.00 29.880 1/760 1
2,000 0.039 758.00 29.840 1/380 15
4,000 0.078 756.00 29.760 1/189 29
6,000 0.117 754.00 29.690 1/127 39
8,000 0.156 752.00 29.600 1/95 46
10,000 0.193 750.00 29.530 1/76 52
15,000 0.290 745.00 29.330 1/50 63
20,000 0.387 740.00 29.130 1/38 72
30,000 0.580 730.00 28.740 1/25 84
50,000 0.967 710.00 27.950 1/15 101
100,000 1.930 660.00 25.980 2/15 125
200,000 3.870 560.00 22.050 1/4 152
500,000 9.670 260.00 10.240 2/3 192
760,000 14.697 0 0 1 Atmosphere 212
!
WARNING
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IM 178 / Page 19
Charging the system
1. Afterallrefrigerant piping iscompleteandthesystemhas
been evacuated, it can be charged as described in the
paragraphsfollowing.Connecttherefrigerantdrumtothe
gauge port on the liquid shutoff valve, and purge the
charginglinebetweentherefrigerant cylinder and the valve.
Then open the valve to the midposition.
2. If the system is under a vacuum, stand the refrigerant
drum with the connection up, open the drum and break
the vacuum with refrigerant gas.
3. With a system gas pressure higher than the equivalent of
a freezing temperature, invert the charging cylinder and
elevate the drum above the condenser. With the drum in
this position and the valves open, liquid refrigerant will
flow into the condenser. Approximately 75% of the total
requirement estimated for the unit can be charged in this
manner.
4. After 75% of the required charge has entered the con-
denser, reconnect the refrigerant drum and charging line
to the suction side of the system. Again purge the con-
necting line, stand the drum with the connection side up,
and place the service valve in the open position.
Important: At this point, the charging procedure should be
interrupted and prestart checks made before attempting to
complete the refrigerant charge.
Note: It is recommended that the total operating charge per
circuitbestampedontheunitnameplateforfuturereference.
Refrigerant charge
Factory installed DX coils in RDS units are designed for use
withR-22.Thetotalchargepercircuitisthesumofthreevalues:
1. Condensing unit charge — refer to manufacturer’s data.
2. Evaporator coil charge — refer to Table 6.
3. Charge for length of interconnecting piping, installed by
field — refer to Table 7.
Note: The systems consist of one refrigerant circuit on unit
size 800C and two refrigerant circuits containing identical
weightsofrefrigeranton unit size 802C.Thevaluesshownin
Tables 6 and 7 are for each circuit.
Note: The total operating charge per circuit should not
exceed the pumpdown capacity per circuit, specified by the
condensing unit manufacturer.
Table 6. Approximate refrigerant charge per circuit
EVAPORATOR COIL
UNIT SIZE (LBS/CKT/COIL ROW)
800C 3.30
802C* 2.45
*The RDS 802C unit has two refrigerant circuits.
Table 7. Weight of refrigerant R-22 in copper lines (pounds per 100 feet of Type L tubing)
WEIGHT OF REFRIGERANT, LBS./100 FEET
O.D. LINE SIZE VOL. PER 100 FT. HOT GAS SUCTION GAS (SUPERHEAT TO 85°F)
IN CUBIC FEET LIQUID @ 100°F@120°F COND. 20°F40°F
3
⁄8" 0.054 3.84 0.202 0.052 0.077
1⁄2" 0.100 7.12 0.374 0.098 0.143
5⁄8" 0.162 7.12 0.605 0.158 0.232
7⁄8" 0.336 24.00 1.260 0.323 0.480
11⁄8" 0.573 40.80 2.140 0.550 0.820
13⁄8" 0.872 62.10 3.260 0.839 1.250
15⁄8" 1.237 88.00 4.620 1.190 1.770
21⁄8" 2.147 153.00 8.040 2.060 3.060
25⁄8" 3.312 236.00 12.400 3.180 4.720
31⁄8" 4.728 336.00 17.700 4.550 6.750
35⁄8" 6.398 456.00 24.000 6.150 9.140
41⁄8" 8.313 592.00 31.100 8.000 11.190
Gas piping
See the “Installation” section of the gas-fired furnace instal-
lation manual, Bulletin No. IM 684 or 685.
Fuel oil piping
See the “Installation” section of the forced draft oil-fired
furnace installation manual, Bulletin No. IM 198.
Contractor coil piping
Contractorcoilshavefinheightnogreaterthan36"(914mm).
Coil connections are on the same side of the unit opposite
the drive. Refer to Table 8 for threaded connection sizes for
chilled water, hot water, and steam coils. Evaporator coil
connection sizes are based on the specific distributor and
Unit Piping
nozzle size selected for the given design conditions. See the
MS-85 Coil Selection Program output for sweat connection
information.
Table 8. Contractor coil connections based on fin height
CONTRACTOR COIL CONNECTION SIZE
1.50 NPT 2.00 NPT 2.50 NPT
5WH, 5MH 12-36 — —
CHILLED 5WL 12-18 21-30 33-36
WATER 5WS, 5MS 12-18 21-30 33-36
5WM, 5WD — — 12-36
EVAPORATOR 5E* See MS-85
Coil Selection Output
HOT WATER 5W*, 1-Row 12-36 — —
5GA, 5JA–1-Row — 12-36 —
STEAM 5GA, 5JA–2-Row — — 12-36
8GA, 8JA — — 12-36
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