McQuay RAH 047C Installation Manual

Table of

.

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3

Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3

Receiving Inspection . . ...’..... . . . . . . . . . . . . . . . ...3

Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...3

Typical Component Locations., . . . . . . . . . . . . . . . . ...4

Typical Unit Sections,...,.,., . . . . . . . . . . . . . . . . ...7

Control Locations . . . . . . . . . . . . . . . . . . . . . . . . . . . ...8

Control Panel Locations, . . . . . . ., . . . . . . . . . . . . . ...9

Controls, Settings, and Functions . . . . . . . . . . . . . ...11

Mechanical installation . . . . . . . . . . . . . . . . . . . . . . . ...13

Receiving Inspection . . . . . . . . . . . . . . . . . . . . . . . . ...13

Unit Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...13

Roof Curb Assembly and Installation . . . . . . . . . . . ...15

Post and Rail Mounting, . . . . . . . . . . . . . . . . . . . . ...16

Rigging and Hand[ing . . . . . . . . . ., . . . . . . . . . . . . ...16

Split Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...17

Reassembly of Split Units..,.. . . . . . . . . . . . . . . ...17

Installing Ductwork, . . . . . . . . . . . . . . . . . . . . . . . . ...21

Installing Duct Static Pressure Sensor Taps ., .,....21

Installing Building Static Pressure Sensor Taps . . ...22

Condensate Drain Connection ., . . . . . . . . . . . . . . ...23

Field Refrigerant Piping and Charging of DX Coils ..24

Unit Piping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...26

Vestibule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...29

Damper Assemblies . . . . . . . . . ., . ., . . . . . . . . . . ...31

Cabinet Weatherproofing . . . . . . . . . . . . . . . . . . . . ...34

Electrical installation, . . . . . . , . . . . . . . . . . . . . . . . ...35

Field Power Wiring . . . . . . . . . . . , . . . . . . . . . . . . . ...35

Field Control Wiring, ..,....., ., . . . . . . . . . . . . ...37

Preparing Unit for Operation. . . . . . . . . . . . . . . . . . ...37

Release of Spring Mounts . . . . . . . . . . . . . . . . . . . ...37

Adjustment of Supply Fan Thrust Restraints . . . . . ...38

Adjustment of Spring Mounts,.. . . . . . . . . . . . . . . ...38

Seismic Restraints . . . . . . . . . . . . . . . . . . . . . . . . . ...38

Sequences of Operation . . . . . . . . . . . . . . . . . . . . . ...39

Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...39

Fan Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...39

Economizer Operation . . . . . . . . ., . . . . . . . . . . . . ...40

Heating Operation . . . . . . . . . . . . . . . . . . . . . . . . . . ...40

Typical Compressor Staging Outputs. . . . . . . . . . . ...42

Typical Power Circuits With Controls . . . . . . . . . . . ...42

Typical Main Control Circuit (VAV Units) . . . . . . . . ...43

Typical Main Control Circuit (CAV-ZTC Units) ,. . . ...44

Typical Main Control Circuit (CAV-DTC Units) . . . . ...45

Typical Actuator Control Circuit . . . . . . . . . . . . . . . ...46

TypicalSupply/Return Fan Control Circuit, . . . . . . ...46

Typical Gas Furnace Control Circuit

(Modulating Burner, Mixed Air Intake) . . . . . . . . ...47

Typical Electric Heat Control Circuit (Multistage) . ...48

Unit Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...49

Enthalpy Control . . . . . . . . . . . . . . . . . . . . . . . . . . . ...49

Part Winding Start. , .,......, . . . . . . . . . . . . . . . ...49

Ground Fault Protection . . . . . . . . . . . . . . . . . . . . . ...49

Phase Voltage Monitor . . . . . . . . . . . . . . . . . . . . . . ...49

Optional Remote Monitoring and Control Panel . . ...50

Remote Monitor Panel . . . . . . . . . . . . . . . . . . . . . . ...50

External Time Clock, . . . . . . . . . . . . . . . . . . . . . . . ...50

Smoke Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . ...50

Freeze Protection . . . . . . . . . . . . . . . . . . . . . . . . . . ...50

Duct High Pressure Limit . . . . . . . . . . . . . . . . . . . . ...51

Variable inlet Vanes . . . . . . . . . . . . . . . . . . . . . . . . ...51

ConvenienceReceptacle/SectionLights . . . . . . . . ...55

Check, Test, and Start Procedures . . . . . . . . . . . . . ...55

Before Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...55

Power-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...56

Fan Start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...56

Economizer Start-up . . . . . . . . . . . . . . . . . . . . . . . . ...56

Heating System Start-up. . . . . . . . . . . . . . . . . . . . . ...57

Cooling System Start-up.....,.. . . . . . . . . . . . . . ...57

Adjusting MicroTech Controls&Servicing . . . . . . . ...57

Air Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...58

Final Control Settings . . . . . . . . . . . . . . . . . . . . . . . ...60

Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...65

Preventive Maintenance . . . . . . . . . . . . . . . . . . . . . ...65

Unit Storage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...65

Gas Furnace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...65

Bearing Lubrication, .,....... . . . . . . . . . . . . . . . ...65

Setscrews . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...66

Airfoil Supply Fan Wheel-to-Funnel Alignment . . . ...66

Winterizing Water Coils. ..,.... . . . . . . . . . . . . . . ...67

Wiring Diagrams . . . . . . . . . . . ., . . . . . . . . . . . . . . . ...41

Legend, . . . . . . . . . . . . . . . . . . . . ., . . . . . . . . . . . . ...41

Typical Power Circuit With Power Pack Only. ,. . . ...42

Installation and maintenance are to be performed only by qualified personnel who are familiarwith local codes
and regulations, and experienced withthistypeof equipment. Caution: Sharpedgesand coilsurfacesare apotential
injury hazard. Avoid contact with them.

Page2/lM487

Service and Warranty Procedure . . . . . . . . . . . . . . ...67

In-Warranty Return Material Procedure . . . . . . . . . ...67

Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . ...67

Product Warranty . . . . . . . . . . . . . . . . . . . . . . . . . . . ...68

Introduction

This manual provides general information about the “C” vin­tage McQuay RoofPak applied rooftop unit, model RAH. In ad-

I

dition to an overall description of the unit, it includes mechani­cal and electrical installation procedures, commissioning pro­cedures, sequence of operation information, and maintenance
instructions. For further information on the optional forced draft
gas fired furnace, refer to Bulletin No. IM 484.

The MicroTech Applied Rooftop Unit Controller is available
on “C” vintage roof mounted air handlers. For a detailed de­scription of the MicroTech components, input/output configura­tions, field wiring options and requirements, and service pro­cedures, refer to Bulletin No. IM 483, “MicroTech Applied Roof-

R AH

RoofPak

~~~~~e= [-

047 (Small Cabinet)
077 (Large Cabinet)

top 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

Variable Air

Constant Air Volume, Zone
Temperature Control (CAV-ZTC)

Constant Air Volume, Discharge
Temperature Control (CAV-DTC)

Nomenclature

–047CSE

1

~ Designvintage

Rooftop Unit

Control Configuration

Volume (VAV)

Operation Manual

Bulletin Number

OM 108
OM 109

OM 110

Heat Medium

A = Natural Gas
E = Electric
S .

Steam
W = Hot Water
Y = None

Cooling Coil Size

S = Standard (Low Airflow)
L = Large (High Airflow)
Y = None

Receiving

When the equipment is received, all items should be careful­ly checked against the bill of lading to be sure all crates and
cartons have been received. All units should be carefully in­spected for damages when received. If any damage is notic­ed, the carrier should make the proper notation on the delivery
receipt acknowledging the damage.

dirty during shipment (winter road chemicals are of partic-

If the unit has gotten

Inspection

ular concern), it should be cleaned off when received. The

carrier should also fill out a Carrier Inspection Report. The
McQuay International Traffic Department should then be con-

tacted at [phone].

The unit nameplate should be checked to make sure the

voltage agrees with the power supply available.

IM 487 I Page 3

Typical Component Locations

Figures 1 through 3 show typical RAH units with the location of the major components and also lists some major dimensions.

These figures are for reference only. See the certified submittals for actual specific dimensions.

Figure 1. Blow-Through Configuration (Unit Size 077C Shown)

Plan View

Bottom Return ~r Openin9 -

,,

(15;mm~

L

,!

(15;mm) ~

(254mm)

10“

r

I--A--I

optional Outside &
Return Air Dampers

f

11

—— —.

r

I
I

,-_l ~

l,,
l,,
I

-r’

-_——

L

Control Entrances _

7/*1’ Diameter Knockout

11/# MPTcondensateDrain Connection

‘I

/’

/’

/

j

(2J’mm)

L powerEntrances

3“ Diameter Knockout
(2 Places)

,,

, Bottom Discharge

Opening

Optional Exhaust Dampers

r

\ ‘r

,’

+ llL-==L=-1~

/

~ Optional Back Return Air

Unit Size 047C Medium Cabinet

II

/

Opening 93.5” (2375mm) Long

Optional Return Air Fan

,,./

g.

-.,

,,+

[<

.’.,
~,.,

-.
<.. .,

.,:/

G

/

L~i,tese.tiofl

L

Optional Outside
Louvers (Both Sides)

Elevation

supply Air Fan

T ‘i-

\

Cooling Coil

r

+

~.—----

.

/

i’

Unit Size 077C Large Cabinet

Description

With Flat Cooling Coil

Wth Staggered or

No Cooling Coil

II
,,

\

Heat Section (Natural Gas, Steam,
Hot Water, Electric)

“A”

(1$5)

(1:5)

Discharge Plenum

Main Control Panel
(Optional)

Dimensions in Inches (mm)

“B”

(::5)

(1%8)

“c.

(2%4)

(2:4)

“D,*

41.8

(1062)

41.6

(1062)

page 4 I IM 487

Figure 2. Draw-Through Configuration with SWSI Supply Fan (Unit Size 077C Shown)

Plan View

Optional

Bottom Return Air Opening

1

r

Outside & Return Air Dampers

1Ilz” MPT Condensate
Drain Connection

r

Bottom 13scharge Opening

r

10’”

(254mm)

I

~Bfl ‘~(15.%m)

~——~.

11,

II . .

~.o.

01

\

l-]

c

1[

7“’

Optional Back Return Air
Opening 93.5” (2375 mm) Long

Heating/Cooling Coil

Optional Exhaust Dampers

Optional Return Air Fan

\

T

D

I

/

r

.——_———.——_.—————————

L

/

Elevation

\ I

L ~lter section

Optional Outside Air
Louvers (Both Sides)

Control Entrances _
718”Diameter Knockout

-+-t

Water

\

Supply Air Fan

Power Entrances
3“ Diameter Knockout
(2 Places)

r

.

L-

Main Control Panel (Optional)

Lrnit siZe 047C Medium Cabinet

~

Unit Size 077’CLarge Cabinet

~

IM 487 I Page 5

——— ————— .

~_____-–––-––__

—.—.—.—.—.—.—.—

*-------------

L------------, - !

;-----

----– –,- Z--114

+--- ___7______4,,4,,

>

L______7L__-_--Jlo

F--–-.+-––-----1!

Jai!

w

:/’

L

-––7----r–_–T____

---1--__l–---:____

~.–-– -—————-—-

,-—-—-—

~_-–- —_—-—-———-

-—-—

J
1

-—--

~---- —----

I

7’

—————

—————.

IL

—---—- -—-

II

l_–__ll____ll____ll____

I
!

1, 11

q

+

I

I

I

=x

-—--

I

T

al

v

q-

5

I/

I

—

Typical Unit Sections

—

The individual sections that make up a rooftop can vary from unit to unit. All available sections are shown below in Figure 4.

Figure 4a. Typical Unit Sections (Draw-Through and Blow-Through with DWDI Supply Fan)

Note: Views shown for 047C family. Not to scale

RET.&lR
0~/HOOD‘

a

PLENUM

u

30L DA

II

ECONO

s

ECONO/R&

R

MlXlNCBOX

,:
.:

: !0,,

n

OPT

EV&P
COOL

8LANK

n

[:

?- . ...,

!. /---

❑

[1

S6 FfiN

,----

,-,

--

II

---

PLEN

J

Figure 4b. ~pical Unit Sections (Draw-Through with SWSI Supply Fan)

Note: Views shown for 047C family. Not to scale.

FILTER

-.
TA/30

:>
:.

,:

i

65/95

,!

“$;

,,

.,

,,

[

STAGG

pl

I

OL~NK

[

OLONK

u

OPT
EVR?

COOL

.

BLANK

u

1

.

/

h-w

HEbT

IM 487 I Page 7

Control Locations

All controls on the RAH are optional. If controls are ordered,
Figure 5 shows the locations of the various control com­ponents mounted throughout the unit. See “Control Panel
Locations” for the locations of control components mounted
in control panels. Additional information is included in Table
2, “Controls, Settings, and Functions,” and the wiring diagram

Figure 5. Control Locations

Oischarge Plenum Section

Blow-through coil SeCtiOn

legend which is included in the ‘rWiring Diagrams” section
of this manual. Figure 5 shows blow-through heat and blow­through coil sections. These sections are also available in the
draw-through position. All controls mounted in the blow­through section would be located in the same position within
the draw-through section.

Return Air Economizer _

C9, 10 (Optional)

ACT1 (Optional)

C19, 20
(Optiona

RAT

ACT2

LTI 1 (OptiOnal)

SUpply Fan Section

Filter SeCtiOn

-/

SII, REC1l
(Optional)

Blow-through Heat

7

Fka

1 [[

Section

SD2 (Optional)

L

ACT6 (Optional)

RAE (Optional)

\\l v-’\ \ \

\oA,

SD1 (Optional)

~ SAT

\~cT~

VM1 (Optional)

Optional)

(Optional)

Page 8 / IM 487

See page 41 for designationldescription.

Control Panel Locations

The unit control panels and their locations are shown in the following figures. These figures show a typical unit configuration.
Specific unit configurations may differ slightly from these figures depending on the particular unit options.

Main Control Panel
Power Pack Only

..-” ”— ”---- . ..

/.”.

~~

(bii‘“

\ /’

‘>\

,.

,.

.. .

.. ... ... ..- ... .

PANEL

Component Locations

.

..

1’

\

~,.,

\,

‘ “.

;

/’

,,

,/

./.

See Page 41 for designationldescription.

~..-.. —-----

”

.,.

,/’

./

/’ --

fj

i

%

,., . . . . .

\

‘.lm

,/’” ..

,! ::;
,,

+-.!:-:--: @)

\

RE61WRIWM

~\

x.

.,. ,

. ..

I

i

I
I

1,

“..b /

\

. ... ... ..-

\

1 ~

\

..

\

----

~;,

rB5 I

rBl 0 !

,./

,./

. .

.,

..

..-

\

\

\

I
I

I

;

;

...

‘\

,.

\

\

I

i

/’

/’

,.

/

IM 487 I Page

9

Main Control Panel

---

IKE”P.D/
.——.

‘L

0===[

❑ —

Component Locations

I r

T1

. .

M2@

I

u

c

u

Control

Box

—

Component Locations

.

..-

Elmml!q

TB

13

---

..­TB

12

---

I

.

II

I
I
I

/“”

See Page41 for

designation/description.

Page 10 / IM 487

\- “,

‘.””’”OS: ‘N,

\

\

\

pf$’ ,,.1, ‘-’

\

\

\

,.

\

,.

\

.,. -

,.-,[:, .

\

‘,,(; , .

.

\

\

. ~,

,.’ ;’. ,

‘,::’-,

\z.,

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, any reset information, its location,
any device setting, any setting ranges, differentials, and the device part number.

Table 2. Controls, Settings, and Functions

Symbol

ADI

DHL

FS1

MAT

MCB1

OAE

OAT

OBA, B, & C

PC 5&6

PC?

Description

ADI Board

Duct high limit

Freezestat

Mixed air temperature
sensor

Microprocessor Control
Board

Enthalpy control
(electromechanical)

Enthalpy control
(electronic)

Outside air temperature
sensor

Output Boards A, B, or C

Filter switch

Differential pressure switch

Function

Collects and conditions

Prevents excessive VAV duct pressures; shuts

Shuts off fans, opens heating valve and closes out­door damper if low air temperature at coil is detected.

Senses mixed air temperature; sends signal to MicroTech
controller,

Processes input information and controls output relays as
appropriate.

Returns outside air dampers to minimum position when Auto
enthalpy is too high.

Returns outside air dampers to minimum position when Auto
outside air enthalpy is higher than return air enthalpy
(used with RAE).

Senses outside air temperature; sends signal to
MicroTech controller.

Holds MicroTech solid-state output relays.

Turns on clogged filter light on status panel.

Senses supply fan pressure to prove airflow.

analog and digital inputs. NIA

off fan. Auto

Auto

NIA

NIA

NIA

NIA

Auto

Auto

Reset

I

Location

Main control

Main control panel

Heating section

I

Inlet of supply fan

Main control box

Economizer section

Economizer section

Under condenser section N/A
Outside wall of discharge (25”C)
plenum section.

Main control box

panel NIA

Setting

NIA

3.5” W.C.(872 Pa)

38° F or as required

(3”C)
NIA 3K ohms at 77° F

I N/A

“B” or as required A—O

Fully CW past “D” A—D
(when used with

RAE)

NIA NIA

0.05-5.0” W.c,
(13-1245 Pa)

35-450 F
(2-7oC)

(25”C)

I NIA

(20c)

Humid.: 50/o fixed

3K ohms at 77° F

Range

Dlfferentisl

UIA
05” W.C. (13 Pa),

ixed

+

+

+

NIA

0.05” WC.

Part #

858160B-05
654938B-01

665422B-01
(16 position)
665422B-02
( 8 position)
665422B-03
( 4 position)

654936B-01

RAE

RAT

SAT

SB1 & 2
SD1
SD2

SPS1

SPS2

z

*

co
+

SPS5

\

-o

&

CD

Return air enthalpy sensor

Return air temperature

sensor

Supply air temperature
sensor

Staging Board 1 or 2
Smoke detector, supply air
Smoke detector, return air
Duct static pressure sensor Converts static pressure signals to voltage signals and

#1

Duct static pressure sensor COMKMS static pressure signals to voltage signals and

#2

Building static pressure

sensor

Dirty filter pressure sensor

Used to compare return air enthalpy to outside air en-

thalpy (used with OAE).

Senses return air temperature; sends signal to MicroTech NIA

controller.

Senses discharge air temperature; sends signal to
MicroTech controller.

Provides stepped cooling or heating control.
Initiates unit shutdown if smoke is detected.
Initiates unit shutdown if smoke is detected.

sends them to MicroTech controller.

sends them to MicroTech controller.

Converts static pressure signals to voltage signals and NIA
sends them to MicroTech controller.

Senses pressure drop across first filter bank and sends NIA
signal to MicroTech controller,

NIA

NIA

NIA
Manual
Manual

NIA

NIA

Return air section

Discharge air section

Main control box
Discharge air section
Return air section
Main control box

Main control box

I I

I NIA I 3K ohms at 770F

I NIA

NIA NIA

NIA
I NIA I NIA
] N/A

NIA o to 5 ‘f WC.

I (25”C)
13K ohms at 7T” F

(25oC)

NIA

Io to 5“ WC.

(0-1245 Pa)

1-8 VDC out

N/A

NIA

N[A

NIA

I 6582!35B-05

I

658295B-01

I

495450B-05

I

1

495450B-05

I

Contined on next page

CD

Table 2. Controls, Settings, and Functions (continued)

N

z

.P
co
4

Symbol

SPS6

S1 System switch
TD9 & 19 Part winding start liner (fans) Reduces inrush amp draw on start-up.
ZNT1, 2, & 3 Space temperature sensors Senses space temperature; sends signal to

GAS HEATI

NG CONTROLS

AS

FD

FLC

FSG Flame safeguard Proves pilot flame and controls main gas valve.

GV1 Pilot gas valve Opens to allow flow of gas to pilot burner.

GV2, 3

HL22 Filter high limit control Opens furnace control circuit on temperature rise.

HL23 Final filter high limit control Opens furnace control circuit on temperature rise.

HPR High pressure regulator Regulates pressure to main regulator.

HP5 High gas pressure switch Shuts off burner if pressure goes above setpoint.

LP5 Low gas pressure switch

Description Function

Dirty filter pressure sensor Senses pressure can drop across final filter bank and

air switch

Blower

Flame rod
Fan control Closes to energize fan when heat exchanger is warm. Auto

High limit control

Main gas valves Opens to allow flow of gas to main burner.

sends signal to MicroTech controller.

Shuts off entire control circuit (except crankcase heaters)

MicroTech controller.

Proves presence of combustion air.

Senses pilot flame.

Opens furnace control circuit on temperature rise.

Shuts off burner if pressure goes below setpoint.

ELECTRIC HEATING CONTROLS

HL1 — 8

HL1 — 18
HL31-34 & Primary heater limit control

41-44 temperatures are too high.

HS1

HS3 Switch (momentary), Shuts off electric heat control circuit if heater dead front

Secondary heater limit
control

Switch (toggle),
electric heat

electric heat is removed.

Breaks line voltage to heaters if temperatures are too high.

Breaks control voltage to electric heat contactor if heater

Shuts off electric heat control circuit manually.

Reset Location

NIA

NIA
Auto
NIA

N/A

N/A Gas burner assembly

Auto Gas heating section

Manual

Normally Gas heating section
closed

Normally Gas heating section
closed

Manual Supply air section Opens at 125° F

Manual

N/A

Manual

Auto Gas heating section

Manual

Auto

N/A

N/A

Final filter section NIA

Main control box
Main control box 1 see, fixed

In building space N/A

Gas furnace control 0.4” WC., fixed
section

Gas heating section Closes at 125° F

Gas furnace control
section

Final filter section

In gas line before MPR

Gas heating section 6“ W.C,

Electric heat section Cut out=210° F

Electric heat section Cut out=175° F

Main control box NIA

Electric heat section

Setting

N/A

(100 Pa)
N/A

(52”C)
Opens at 100” F
(36oC)

Opens at 200” F
(93”C)

NIA

NIA

N/A

(52°C)
Opens at 1650F

(74”C)
As specified

(1993 Pa)

4“ W.c.

(996 Pa)

(99”C)

(79”C)

Cut in=145° F

(63oC)

NIA

Range

o to 5“ W.c.
(0-1245 Pa)

1-6 VDC out
NIA
N/A
3K ohms at 71° F

(25”C)

N/A

NIA NIA
65-220” F

(18-104°C)
50-205° F
(10-96oC)

100-2500 F
(38-121”C)

NIA N/A

N/A

NIA

N/A

N/A

10.0to 13.0” W.c.

(2491-3238 Pa)
5-35 ‘c W.c.

(1245-8718 Pa) (249-747 Pa)

3-21“ W.C.
(747-5231 Pa)

N/A

NIA

NIA

NIA

Differential Part #

N/A 495450B-05

NIA 012550B-00
N/A
NIA

NIA

25° F, adjustable
(14”C)

250 F, fixed
(14”C)

N/A 344864B-00

N/A See IM 484

250 F, fixed 479388B-01
(14”C)

25” F, fixed 479388 B-046
(14”C)

NIA See parts catalog

1-3” WC, See parts catalog

1-3“ W.c. See parts catalog
(249-747 Pa)

NIA

300 F, fixed 658245B-01
(16”C)

NIA

NIA 336963A-00

262101D-O1
See IM 483

330036B-00

365577A-00

340821B-00

See IM 484

654962B-01

237803D-01

Mechanical Installation

The installation of this equipment shall be in accordance with
the regulations of authorities having jurisdiction and all ap­plicable codes. It is the responsibility of the installer to deter­mine and follow the applicable codes.

Unit Clearances

Service Clearance

Sharp edges are inherent to sheet metal parts, screws,
clips, and similar items. Can cause personal injury.

This equipment is to be installed and operated only by an ex­perienced installation company and fully trained personnel.

Exercise caution when servicing equipment.

I
I

I

Allow service clearance approximatelv as indicated in Figure

6 below. Also, it is recommended that a roof walkway bepro-

vialed to the rooftop unit and along at least the two sides of the

Figure 6a. RAH Unit With Housed DWDI Supply Fan

r

,!

(18~mm)

Location

unit that provide access to most controls and serviceable
components.

—24”
[635mm)

Figure 6b. RAH Unit With SWSI Plenum Supply Fan

I r

1 1 I I I I I

F

:E

—No

hLu-

m
g

?

/ Y//////////M//////////&

(18~m)

-WI

r V..

m—_’ / I 1~

rluwl

Walkway

TO Roof

Access

Location

v//4

.

i

8 G 0

Varies With Unit Arrangement

Refer to Certified Drawing & Note

T

,,

(24$mm)

v

1
I I

P

I

‘1

Note:
Sections

with heating and/or cooling coils or DWDI supply

fan must have 96” service clearance on control box side.

Legend:
A= Return Air Section
B=Filter Section
C=Combination Coil Section
D=Heat Section
E=Supply Fan Section
F= Discharge Plenum Section

IM 487 I Page 13

Ventilation Clearance

Following are minimum ventilation clearance recommenda­tions. 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 fence:

The bottom of the screen or fence should be at least one

1.

foot above the roof surface.

2. The distance between the unit and the screen or fence

should be as described in “Service Clearance” above.

3. The distance between any two units within the screen or

fence should be at least 120 inches (3048mm).

Unit(s) surrounded by solid walls:

1, If there are walls on one or two adjacent sides of the unit,

the walls may be any height, If there are walls on more
than 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 inches (2438 mm) on all sides of the unit.

3. The distance between any two units within the walls should

be at least 120 inches (3048mm).

Figure z Overhead Clearance

Do not locate outside air intakes near exhaust vents or other

sources of contaminated air.

If the unit is installed where windy conditions are common,

wind screens should be installed around the unit, maintain-

ing the clearances specified above. This is particularly im­portant to prevent blowing snow from entering outside air
intakes.

Overhead Clearance

1. Unit(s) surrounded by screens or solid walls 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 7).

a. There shall be no overhead obstructions above the fur-

nace flue, or within 9 inches (229mm) of the sides of
the flue box.

b. Overhead obstructions shall be no less than 2 inches

(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 inches (610mm) from the side of the unit.

2“ (51mm) Minimum
Top of Unit
To Overhead
Obstruction

24” Max.

(61Omm)

9“ (229mm) Minimum To Flue
Box Typical All Sides

Page 14 / IM 487

Roof Curb Assembly and Installation

I

The roof curb and unit must be located on a portion of the
roof 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 recom­mended that the unit be located over a noncritical area. It is

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.

Assembly of a typical RAH roof curb is shown in Figures

8a and 8b. Refer to instruction drawing provided with roof curb.
the responsibility of the system designer to make adequate Parts A through H are common to all units having bottom
provisions for noise and vibration in the occupied space.

Integral supply and return air duct flanges are provided with
the RAH roof curb, allowing connection of ductwork to the curb
before the unit is set. The gasketed top surface of the duct

Figure 8a. RAH Roof Curb Assembly Instructions

,,.

(Z!i;;m>+ ~jo~m)

return openings. Depending on the unit length, Parts L and
M maybe included with the roof curb kit to create the correct
overall curb Iength.

.

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.

EOUAL
:W[GT “

SUPPORTS

A

RAH Unit

047C

077C With Flat Cooling Coil and/or

4411 SWSI Plenum Supply Fan

077C With Staggered or No Cooling Coil,

and/or 49fI SWSI Plenum Supply Fan

Assembly Instructions:

1.

Set c;rbing parts A thru H per dimensions shown over roof opening or on a level surface. Note location of return and SU!JDIVair oReninW
If applicable, set other curbing parts (D, L, M, etc.) in place making sure that the orientation agrees with the assembly instrfictions. Ch[ck

2.

alignment of all mating bolt holes. See Detail “A’.
Bolt curbing parts together using fasteners provided. Tighten all bolts finger tight.

3.

Square entire curbing assembly and securely tighten all bolts.

4.

Position curb assembly over roof openings. Curb must be level from side to side and over its length. Check that top surface of the curb

5.

is flat with no bowing or sagging.
Weld curbing in place. Caulk aH seams watertight. Remove backing from 0.25 thick

6.

by crosshatching.
Flash curbing into roof as shown in Detail “B”.

7.

Parts E and F are not required on units with no return shaft within the curb perimeter.

8.

Parts G and H are not required on units with no supply shaft within curb perimeter.

9.

3imensions in. (mm)

“x”

(::5)

(1:5)

(1%5) (1%8)

Unit Base

Curb Gasketing
2 x 4 Nailer Strip
Galvanized Curb
Cant Strip (Not Furnished)
Roofing Material (Not Furnished)
Rigid Insulation (Not Furnished)
C&nterflashing (Not Furnished) ~ ~A,N “NIT CURB
Flashing (Not Furnished)

“y,.

(;: )

(::5)

x 1.50 wide gasketing and apply to surfaces shown

IM 487 I Page 15

Post and Rail Mounting

When mounting by Post and rail, the structural support should

run the full length of the unit to prevent any deflection of

be

the cabinet. The structural member should be located at the

base of the unit as shown in Figure 9 assuring the shaded

area is well supported by the structural member.

Figure 9. Post and Rail Mounting

4

,,

­(12~m’m)

‘2’;;”)-

l’rl T

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.

If resilient material is placed between the unit and the rail,
insert a heavy steel plate between the unit and the resilient
material to distribute the load. Cabinet penetrations (electrical,
piping, etc.) should be sealed in a professional manner to pro- ­tect against moisture and weather.

Rigging and Handling

Lifting brackets with 2 inch (51mm) diameter holes are pro-

vialed on the sides of the unit. Figure 11 shows an example of the rigging instruction label

Use spreader bars, 101 to 105 inches (2565 to 2667mm)
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 in-

termediate period, set the unit in a reasonably level position

!l_l!!l_

------ ----

“ Maximum recommended width for structural member

(127mm) to allow for adequate space for duct connections and
electrical entry

with adequate support.

shipped with each unit.

All lifting points must be used. Adjustment maybe required
for the middle cable in a six-cable arrangement.

-------

is 5“

Figure 10. Rigging and Handling Instruction Label

Rigging and Handling Instructions

Unit has either four or six lifting points (six-point shown below),

Caution: All lifting points must be used.

Note: Rigging cables must beat least as long as distance “A”.

Sprea
Requi

/v

Lift Only As Indicated

Caution: Lifting points may not
be symmetrical to center of grav­ity of unit. Ballast or unequal
cable lengths may be required.

Page 16 / IM 487

I

Lifting Points and Cable Lengths

To determine the required lifting cable lengths and whether
four- or six-point lifting is required, use Table 3 and Figure 11.

Referring to Figure 11, note that Dimension A is the dis­tance 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
the inner lifting points for six-point lifting. This can be used
to roughly determine the required length of the middle cables

for six-point lifting. Dimension A can be determined by sub-

tracting Dimension X from Dimension Z (i.e., A = Z - X).
Where:

Z = Total unit length in inches (refer to certified drawings for

this dimension).

Figure 11. Unit Type RAH

4 Lifting Points

X = Refer to Table 3 for this dimension

If A < 288 inches (7315mm), 4-point lifting is sufficient.
If A > 288 inches (7315mm), 6-point lifting is required.

Table 3. “X” Dimension (See Figure 11)

Type of Economizer Section

100%OA

Plenum
O —

2.00/o OA

O — 100°/0 Economizer

O — 100°10 Economizer

With Return Fan

I

6 Lifting Points

047C

o

48” (1219 mm)

48” (1219 mm)
72” (1829mm)

72” (1829 mm)

72” (1829mm)

72” (1829 mm)

96” (2438 mm)
96” (2438 mm)

077C

0

Split Units

Althouqh RAH units typically ship from the factory in one

piece, units with blow-through sections maybe factory split at
the supply fan bulkhead, to be recoupled on the roof. This
configuration would be ordered if shipping length or weight

Reassembly

Field reassembly of an RAH unit that has shipped split at the
fan takes place in two places:

1. Setting the sections and mechanically recoupling the
cabinet.

2. Reconnecting power and control wiring if optional power
pack and/or controls are used.

Setting the Sections
and Cabinet Reassembly

The steps required to set the unit and reassemble the cabinet
are shown in Figures 12a through 12c. The following items
should be noted:

1. Top cap and plywood covers must be removed before the
sections are set together, but the steel retainer clips must
be left in place to secure the bulkhead. Refer to Step #1
in Figure 12a.

limitation prevented a packaged RAH from being ordered.

A single nameplate is attached to the air handler section

and power is fed to both sections through the optional main

control box as it would be in a packaged RAH unit.

of Split Units

2. Both sections must be lowered into place carefully to make
sure that the roof curb engages the recesses in the unit
base.

3. All seams at the split must be caulked watertight after
recoupling the sections, as shown in Step #3 of Figure 12b.

Reconnecting Power and Control Wiring
(Units With Optional Factory Wiring)

The discharge sections contain power and control harnesses
which have their excess length in the blank or heat section
that is normally immediately downstream of the fan. Once
the sections are physically reconnected, the ends of the
power harness are fed back through the unit base into the
junction box, per the unit’s electrical schematics.

IM 487 I Page 17

Care must be exercised to connect the proper power block
and maintain proper phasing.

I

When reconnection of the power wires is complete, the in­ner raceway cover in the blank or heat section must be
reinstalled. Step #4 of Figure 12c shows a typical installation

of the raceway cover.

Figure 12a. Reassembly of Split Unit

Step 1

Prepare units for reassembly as shown.

Control harnesses may be run by removing the external
raceway covers on either side of the unit split. The excess
harness length may be removed from the external raceway
on the discharge side of the split, routed along the raceway

I

through the bushed hole in the fan section, and into the junc-

tion box where control wiring terminal blocks are provided for

reconnection. All electrical connections should be made per

the unit’s electrical schematics. Re-install the external raceway
covers after routing of the control wires is complete.

REMOVE PLYWOOD AND RETAINING
ANGLES FROM UNIT AND DISCARD

k

L

REMOVE SCREWS ON FAN PANEL, BUT
LEAVE RETAINER CLIPS IN PLACE;
SAVE SCREWS FOR STEP 3

OISCHARGE END OF UNIT

f

Step 2

Set fan end of unit and discharge end of unit in place.

Page 18 I IM 487

r

Figure 12b. Reassembly of Split Unit

Step 3

Caulk and install parts as shown.

\

CAULK VERTICAL
SEAM

SPLICE COVER PROVIDED

f

‘\

)

“%

[

INSTAL
SCREWS PROVIDED

NUT CLIP-ON PROVIDED

#lo

/

IM 487 / Page 19

Figure 12c. Reassembly of Split Unit

Step 4

Note: The fan diffuser is used in a

blank heat section or in a steam and
hot water heat section only.

A

Step 5

Make electrical connections.

Page 20 I IM 487

~ INNER RACEWAY COVER IS

TO BE INSTALLED AFTER
WIRES ARE ROUTED
(NOTE: SEE STEP 5)

Installing

Ductwork

On bottom-supply/bottom-return units, 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 the unit’s duct opening if a McQuay roof
curb is not used. Do not support the total weight of the duct­work from the unit or these duct flanges. Refer to Figure 13.

Units with optional back return, side discharge, or end
discharge all have duct collars provided. The discharge duct
collars on a side discharge unit are exposed by removing the
plenum section access door and the door gasketing.

Flexible connections should be used between the unit and

ductwork to avoid transmission of vibration from the unit to
the structure.

Ductwork should be designed per ASH RAE and SMACNA
recommendations to minimize losses and sound transmission.
Where return air ducts are not required, it is recommended

Figure 13. Installing Ductwork

UNIT DUCT

OPENING

\ll

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 ASH RAE and SMACNA recommendations
and local building codes.

On units with side discharge and a main control panel, ac­cess to plenum mounted components becomes difficult
once ductwork is installed.

Installer must provide access in the ductwork for plenum
mounted controls.

I

UNIT BASE

/

I

T‘

9.76”

(248mm)

I

CONNECTOR

For all VAV units, duct static pressure taps must be field in­stalled and connected to the pressure sensors in the unit. Sen­sor SPSI is standard; additional sensor SPS2 is optional.
These sensors are located at the bottom of the main control
panel next to terminal block TB2 (see “Control Panel Loca­tions” in the “Unit Description” section of this manual).

The duct static pressure sensing tap must be carefully
located and installed. Improper location or installation of the
sensing tap will cause unsatisfactory operation of the entire
variable air volume system. Following are pressure tap loca­tion and installation recommendations. The installation must
comply with local code requirements.

fi’

Ii!,$

Installing

\

.DUCT FLANGE
IN ROOF CURB

Duct Static Pressure Sensor Taps

~ ROOF CURB

Fragile sensor fittings. May damage pressure sensor.

If tubing must be removed from a pressure sensor fitting, use

Do not wrench the tubing back and forth to remove or

care.
the fitting may break.

1. Install a tee fitting with a leak-tight removable cap in each
tube near the sensor. This will facilitate connecting a

manometer or pressure gauge if testing is required.

IM 487 / Page 21