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Installation and Maintenance IM 782-2
Group: Destiny Air Handler
Destiny™ Air Handler
Sizes 002 to 030
Part Number: IM 782
Date: March 2007
© 2007 McQuay International
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Contents
General Information . . . . . . . . . . . . . . . . . . . . . . . . . 3
Smoke Control and Management Systems. . . . . . . . . . . . . . . . . . . 3
Receiving and Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Storing the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Installation Guidelines . . . . . . . . . . . . . . . . . . . . . . . 5
Attaching the Mixing Box. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Service Clearances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Rigging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Unit Leveling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Panels and Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Fan Section Doors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Mounting Actuators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Reversing the Coil Handing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Reversing the Drive Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Hanging the Unit from a Ceiling . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Piping and Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Water Cooling Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Direct Expansion Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Steam Coils. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Water Heating Coils . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
Drain Pan Traps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Internal Isolation Assembly Adjustment . . . . . . . . . . . . . . . . . . . . 14
Before Operating the Unit . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Spring Mount Adjustments—Twin Fan Units . . . . . . . . . . . . 14
Electric Heat Section (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Open Coil Duct Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Single Point Power . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Quality Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Electric Heat KW Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Heater Amps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Electric Heat Safety. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Overcurrent Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Thermal (Over temperature) Protection. . . . . . . . . . . . . . . . . 18
Fan Interlock Method: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Airflow Switch: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
Electric Heat Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Field Power Wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Supply Power Wiring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Electrical Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Operation Guidelines . . . . . . . . . . . . . . . . . . . . . . 20
Startup Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
Before starting the unit: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
After first 48 hours of operation: . . . . . . . . . . . . . . . . . . . . . . 21
Operating Limits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Fan Vibration Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Vibration Causes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Service and Maintenance . . . . . . . . . . . . . . . . . . . 22
Periodic Service and Maintenance . . . . . . . . . . . . . . . . . . . . . . . . 22
Ball Bearing Lubrication. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Fan Drive Adjustments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
VM and VP Variable Pitch Key Type Sheaves . . . . . . . . . . . 23
LVP Variable Speed Sheaves . . . . . . . . . . . . . . . . . . . . . . . . 23
MVP Variable Speed Sheaves . . . . . . . . . . . . . . . . . . . . . . . 25
Fan Drive Belt Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
General Rules of Tensioning . . . . . . . . . . . . . . . . . . . . . . . . . 26
Tension Measurement Procedure . . . . . . . . . . . . . . . . . . . . . 26
Coil Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Component Removal and Replacement . . . . . . . . . . . . . . . . . . . . 28
Panel Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Fan Section Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Coil Removal and Replacement . . . . . . . . . . . . . . . . . . . . . . 28
Warranty. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Warranty Return Material Procedure . . . . . . . . . . . . . . . . . . . 29
Replacement Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
Page 3
General Information
WARNING
Improper installation or maintenance can cause
equipment damage or personal injury.
Installation and maintenance must be performed by qualified
personnel familiar with applicable codes and regulations, and
experienced with this type of equipment.
AVERTISSEMENT
Une installation ou un entretien inadéquats peut
endommager l’équipement ou entraîner des blessures
personnelles. L’installation et l’entretien doivent être
exécutés par un personnel qualifié, familier avec les codes
et règlements applicables et possédant de l’expérience avec
ce type d’équipement.
CAUTION
SHARP EDGES AND COIL SURFACES
can cause personal injury. Avoid contact with them.
ATTENTION
Les bords tranchants et les surfaces des bobines sont un
risque de blessure. Ne les touchez pas.
CAUTION
Destiny units are not designed to be weather resistant;
DO NOT install outdoors.
ATTENTION
Les Unités Destiny ne sont pas à l’épreuve des intempéries;
NE PAS les installer à l’extérieur.
Smoke Control and Management Systems
The system design and installation must follow accepted
industry practice, such as described in the ASHRAE
Handbook, the National Electric Code, and other applicable
standards. The installation of this equipment must be in
accordance with regulations of authorities having jurisdiction
and all applicable codes. It is the responsibility of the installer
to determine and follow the applicable codes
WARNING
Improper smoke or fume air handling can result in severe
personal injury or death.
A registered professional engineer must design and approve
the air conditioner and air handler application to make sure
smoke and fume control meet local fire codes and NFPA
requirements for the specific building application.
Due to the wide variation in building design and ambient
operating conditions into which our products can be applied,
we do not represent or warrant that our products will be fit and
sufficient for smoke and fume control and management
purposes. The owner and building designer must consult a
registered professional engineer to satisfy themselves in this
regard.
AVERTISSEMENT
Un traitement inadéquat de l’air contenant de la fumée
peut entraîner des blessures personnelles ou même la
mort.
Un ingénieur professionnel doit faire la conception et
approuver l’unité de traitement d’air et son application pour
s’assurer que le contrôle de la fumée rencontre les codes
d’incendies locaux et les normes NFPA pour l’application
spécifique du bâtiment.
Dû à la grande diversité de conceptions des édifices ainsi que
des conditions d’opération ambiantes dans lesquelles nos
produits peuvent être appliqués, nous n’avançons ni ne
garan-tissons que nos produits seront adéquats et efficaces
quant au contrôle de la fumée. Le propriétaire et le concepteur
du bâtiment doivent consulter un ingénieur professionnel à
cet égard
McQuay IM 782-2 3
Page 4
General Information
Receiving and Handling
1 Carefully check items against the bills of lading to verify
all crates and cartons were received. Carefully inspect all
units for damage when received. Report visible and
concealed damage immediately to the carrier and a file a
claim for damage.
2 Destiny air handler units are thoroughly inspected before
leaving the factory. Install units carefully to prevent
damage.
3 Leave enough space around the unit for proper
maintenance, filter removal, lubrication, belt adjustment,
and removal of coils, if necessary.
4 Use flexible connections on the inlet and outlet duct
connections of the unit.
5 For 002 - 010 sized ceiling hung units, spring isolation of
the cabinet is recommended.
6 All fans are dynamically balanced before leaving the
factory. Carefully inspect fans for rough handling that can
cause misalignment or a damaged shaft.
7 Adequately pitch and trap drain line from drain pan
connection.
Storing the Unit
Store unit on a level surface. If air handling units are to be
stored for any period of time, it is important to rotate the fan
wheel (quarterly, as a minimum) to prevent permanent
distortion of drive components. Keep the fan bearings
lubricated. Grease may settle in the lower part of the bearing,
which may lead to oxidation on the upper portion of the
bearing surface.
Store units indoors in a clean, dry environment on a level
surface. Moisture, debris, and minerals can cause permanent
damage to the cabinet and components. Do not allow
coverings to trap moisture on the galvanized surface.
4 McQuay IM 782-2
Page 5
Installation Guidelines
Attaching the Mixing Box
Mixing boxes ship with Destiny units as a field-installed
option. Attach the mixing box to the intake end of the air
handler using cleats included with the mixing box section.
Figure 1: Mixing Box Installation
Cleat locations
Install the cleats into the interior mounting frames, with the
hardware included as shown in Figure 1.
Cleat
installation
Cleat locations
(sizes 015 and above)
McQuay IM 782-2 5
Page 6
Installation Guidelines
Service Clearances
Leave adequate space around the unit for piping, coils, and
drains. Always have access to at least one side of the unit for
regular service and maintenance. See Figure 2 for servicing
space requirements. Routine maintenance examples include
filter replacement, drain pan inspection and cleaning, fan
bearing lubrication, and belt adjustment. Provide sufficient
space on the drive side of the fan and the connection side of
the coil for shaft and coil removal, if necessary (refer to the
“Coil Data” section in Catalog 580 for information about coil
sizes). Both the fan drive and coil can be field modified to
right or left hand to accommodate clearance restrictions. See
“Reversing the Coil Handing” on page 9 and “Reversing the
Drive Package” on page 11.
Figure 2: Servicing Space Requirements
Vertical unit
Width
Height
For routine maintenance, remove panels on either side of the
unit. See “Panel Removal” on page 8. Optional service doors
are available for the fan and filter sections. Allow sufficient
space for service door(s) to swing completely open, or to meet
the clearance requirement of the section it accesses, whichever
is greater. Service doors are not interchangeable with access
panels on the opposite side of the unit. Determine clearances
before specifying doors.
Have at least 54" of clearance in front of electrical power
devices (starters, VFDs, disconnect switches, and combination
devices). Electrical power devices that are mounted on the side
of the unit typically are 12" deep (see Figure 3).
Figure 3: Service Clearance for Electrical Power Devices
54"
Horizontal unit
Width of
fan section
Top view
coil section
Width of
12"
Width
30.00”
Height
Width
6 McQuay IM 782-2
Page 7
Installation Guidelines
Rigging
Rig units using straps or a sling. Fasten strapping under the
skid that ships with the section. If a field-installed mixing box
is attached, adjust to balance the unit properly.
To avoid damage to the unit cabinetry, use spreader bars.
Position spreader bars to keep cables from rubbing the frame,
connections, or panels. Before hoisting into position, test lift
for stability and balance. Avoid twisting or uneven lifting of
the unit.
Figure 4: Rigged Unit on Skids
Horizontal unit
Unit Leveling
Place the equipment on a flat and level surface (or verify that
unit is level when hanging from the ceiling). Where the surface
irregularities allow the equipment to distort, shim the base of
the unit to a straight line. Distorted units can cause misfit or
binding of the doors and panels and improper draining of drain
pans.
Figure 5: Leveling the Unit
Horizontal unit
Vertical unit
Vertical unit
McQuay IM 782-2 7
Page 8
Installation Guidelines
Panels and Doors
DANGER
Hazardous moving parts, high static pressure, and/or high
voltage. Can cause severe injury or death.
Disconnect and lock ALL electric power off before entering or
servicing unit. Unit may employ multiple power supplies and/or
remote disconnects.
Secure drive sheaves to prevent motors and fan from free
wheeling.
When leaving the unit, use screw or door handle locking
mechanism provided to secure access panel closed and
prevent unintentional entry.
DANGER
Pieces mobiles dangereuses, haute pression statique et/
ou de hautes tensions. Risques de blessures graves, voire
mortelles.
Débranchez et verrouillez toutes les alimentation électriques
avant de pénétrer ou d’intervenir sur cet appareil. Cet appareil
peut étre alimenté par plusieurs sources etlou par
l’intermédiaire de plusieurs disjoncteurs éloignés.
Attachez les disques d’entrainement afin d’éviter que les
moteurs et le ventilateur ne tournent librement.
A Ia sortie de l’appareil, fermer le panneau d’accès avec Ia vis
ou avec le mécanisme de verrouillage de Ia poignée de porte
qui sont founis pour éviter toute entrée inopinée.
Fan Section Doors
1 Use a flat head screwdriver and rotate the screw 1/4 turn as
shown in Figure 7.
2 Rotate door handle 1/4 turn and open the door.
Figure 7: Fan Section Doors
Panel Removal
Destiny air handlers have pocket pull handles in alternate
sections that allow side panels to be easily removed and
handled. To gain access through a side panel, remove the
fasteners along the sides of the panel and lift the panel off
using the pocket pull handle. If the panel you are accessing
does not have a pocket pull handle, remove an adjoining panel
with a pocket pull handle and push the panel out from inside
the unit.
Figure 6: Panel Removal
Mounting Actuators
The installing contractor is responsible for the mounting of all
field-installed actuators. An actuator mounting plate is
provided on the shaft side of the damper frame to
accommodate many actuators. However, due to the number of
options, size variations, and arrangements available, some
actuators may require alternate field provided mounting
hardware. Provide proper support for the actuator to avoid
excessive stress in the cabinet, linkage, or damper shafts.
8 McQuay IM 782-2
Page 9
Installation Guidelines
Reversing the Coil Handing
Coil connections can be switched to the opposite side of the
unit by rotating the coil(s) 180 degrees side to side and
reworking the coil section panel on the opposite side of the air
handler.
Note – Direct expansion (DX) coils require 180 degree rotation
on the top to bottom to locate distributor tubes at the
leaving face of the coil.
CAUTION
Sharp edges and coil surfaces
can cause personal injury. Avoid contact with them.
ATTENTION
Les bords tranchants et les surfaces des bobines sont un
risque de blessure. Ne les touchez pas.
To reverse the coil connections, follow the steps below,
referring to Figure 8 on page 10.
1 Remove exterior panels from both sides of the coil section.
Remove screws that secure the top of the leaving coil face
to the upper track on the inside top of the unit.
2 Lift drain pan condensate connection above the unit frame
flange and slide drain pan, coil(s) and baffles out of unit.
3 Remove screws and remove coil blockoffs.
4 Remove screws holding coil to drain pan and remove coil.
5 Rotate the coil 180° and reposition coil blockoffs to the
entering air side of the coil.
6 Drill holes if required and fasten the blockoffs to the
entering side of the coil.
7 If unit has both heating and cooling coils, position and bolt
heating coil and cooling coil casings together in same
arrangement in the direction of airflow as unit was shipped
from factory. Reheat coils must remain in reheat position;
do not place in preheat position. Fasten the first coil in the
air stream to the entering side of the drain pan using the
same holes provided for the coil before it was rotated.
8 Mark locations and drill holes to align with holes in upper
track.
9 Slide the coil, blockoffs and drain pan assembly back into
unit the same way it was removed. Check the installation
for an airtight fit. Re-install screws that secure the top of
the leaving coil face to the upper track on the inside top of
the unit.
Depending on whether the air handler was purchased from
stock or if it was manufactured for the specific job, the panel
on the opposite side may or may not have predrilled
connection holes.
10 If connection holes need to be drilled, determine the proper
diameter in order to use the existing grommets.
11 Mark connection locations on panel and drill new holes to
accommodate connections and grommets.
12 Plug and seal unused connection holes on opposite side
panel with new solid grommet or other suitable material.
McQuay IM 782-2 9
Page 10
Installation Guidelines
A
Figure 8: Reversing the Coil Handing
Remove screws
1
from the upper track
that hold coil/drain pan
in place
Airflow
2
Remove screws and
3
remove coil blockoffs.
Lift drain pan connection
up and slide coil/drain pan
assembly out.
Mark locations
8
and drill holes
to align with holes
in upper track.
Drill holes in coil header plate
7
flanges, position block offs
and install screws to secure to coil.
Remove screws
4
holding coil to
drain pan and
remove coil.
Rotate coil 180°
5
and reposition in
drain pan.
All coils
except DX
NOTE:
Rotate a DX
(evaporator)
coil 180° TOP
to BOTTOM.
irflow
Distributors
must be on the
leaving air side
of the coil.
Airflow
Drill holes in coil
6
bottom flange
and install screws
to secure to
drain pan.
NOTE:
If a heating coil
is used, position
heating coil in
the same location
as unit was shipped
from factory. Rejeat
coils must remain in
reheat positon; do not
place inpreheat postiion.
Position coil/drain pan
9
assembly in unit and install
screws in upper track.
10 McQuay IM 782-2
Page 11
Installation Guidelines
C-channels are required on all units.
On unit sizes 007 and above, L-channels
on both ends are also required.
Spring Isolators
Reversing the Drive Package
The drive package on the air handler can be changed to the
other side of the blower. The motor base and motor are
attached to back of the fan housing. They can be removed,
rotated 180 degrees, and reattached. The fan sheave can be
removed and reinstalled on the opposite end of the shaft. Refer
to Figure 9. Review “Fan Drive Belt Adjustment” on page 26
when reinstalling the belts.
To reverse the drive package:
1 Loosen the belt adjustment screws to relieve the drive belt
tension.
2 Remove the drive belt and the blower pulley.
3 Loosen the two upper bolts on the motor mounting plate
and slide the motor out from the blower housing mount.
4 Move the top motor mounting bolts to the bottom motor
mounting plate location and vice versa. Fasten securely.
5 Turn the motor 180° and slide it back into the blower
housing mount and tighten bolts.
Note–Change the motor wiring so the motor rotates in the
opposite direction.
6 Install the blower pulley and the belt to the other side of the
blower housing.
7 Adjust belt tension.
Hanging the Unit from a Ceiling
Before hanging, rig and completely assemble the unit.
WARNING
Do not suspend the unit from the top.
The unit top will not support the weight of the unit.
Equipment damage and severe personal injury can result.
AVERTISSEMENT
Ne pas suspendre l’unité par le toit.
Le dessus de l’unité ne supportera pas le poids de l’unité.
Ceci pourrait entraîner des dommages à l’unité ou des
blessures personnelles graves.
The Destiny air handler has circular knockouts on the corner
connections. Remove the knockouts and suspend the unit using
threaded rods and hardware with required C-channels on both
sides as shown in Figure 10. On unit sizes 007 and larger,
L-channels are required on both ends in addition to
C-channels. For 002 - 010 sized ceiling hung units, spring
isolation of the cabinet is recommended. See Figure 10.
Figure 10: Ceiling Hung Installation, Horizontal Units Only
Figure 9: Reversing the Drive Package
Lower motor
mounting
plate bolts (2)
Upper motor
mounting
plate bolts (2)
Belt
adjustment
bolts (2)
McQuay IM 782-2 11
Page 12
Installation Guidelines
Piping and Coils
Follow applicable piping design, sizing, and installation
information presented in ASHRAE Handbooks in the design
and installation of piping. Observe all local codes and industry
standards. Do not apply undue stress at the connection to the
coil headers. Support pipe work independently of the coils.
Water Cooling Coils
Water cooling coil guidelines are listed below. Refer to
Figure 11.
1 Water supply, water return, drain, and vent connections
extend through the end panel of the coil section. All
connections are labeled on the end panel.
2 Water supply and water return connections are copper
sweat on units 002 through 010 and male NPT iron pipe on
units 015 through 030.
3 When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup
pipe wrench to avoid breaking the weld between coil
connection and header.
4 Follow recommendations of the control manufacturer
regarding types, sizing, and installation of controls.
Figure 11: Water Cooling Coil Connections
RETURN
AIR
FLOW
SUPPLY
AIR
RH
FLOW
Right Hand AIr Flow Coil
LH
Left Hand AIr Flow Coil
Direct Expansion Coils
Direct expansion coil connection guidelines are listed below.
Refer to Figure 12.
1 The coil distributor and suction connection extend through
the end panel of the coil section.
2 Check nozzle in distributor for proper tonnage.
3 The thermostat expansion valve must be an external
equalizer tube type. Connect the equalizer tube provided on
the coil (3/16" for units 002 to 010, and 1/4" for units 015
to 030) to the connection on the expansion valve.
4 Use care when piping up the system, making sure all joints
are tight and all lines are dry and free of foreign material.
For typical refrigerant piping, see the condensing unit
product manual.
Figure 12: DX Coil Connections
LIQUID
CONNECTION
AIR
AIR
FLOW
FLOW
SUCTION
CONNECTION
AIR
LH
FLOW
AIR
FLOW
SUCTION
CONNECTION
SUCTION
RH
Right Hand
Air Flow Coil
RH
LIQUID
CONNECTION
Right Hand
Air Flow Coil
Left Hand
Air Flow Coil
LIQUID
CONNECTION
Left Hand
Air Flow Coil
LH
CONNECTION
Steam Coils
Steam coil connection guidelines are listed below. Refer to
Figure 13.
1 All steam coils in units are pitched toward the return
connection.
2 Steam supply and steam return connections are typically
male NPT iron pipe and are labeled on the end panel of coil
section. Connections extend through coil section end panel.
3 When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup
pipe wrench to avoid breaking the weld between coil
connection and header.
4 Support piping independently of coils and provide adequate
piping flexibility. Stresses resulting from expansion of
closely coupled piping can cause serious damage.
5 Do not reduce pipe size at the coil return connection. Carry
return connection size through the dirt pocket, making the
reduction at the branch leading to the trap.
6 Install vacuum breakers on all applications to prevent
retaining condensate in the coil. Generally, connect the
vacuum breaker between the coil inlet and the return main.
Open the vacuum breaker to the atmosphere and design the
trap to allow venting of large quantities of air.
7 Do not drip supply mains through the coil.
8 Do not attempt to lift condensate when using modulating or
on/off control.
9 Size traps in accordance with manufacturers’
recommendations. Be certain the required pressure
differential will always be available. Do not undersize.
12 McQuay IM 782-2
Page 13
10
Use float and thermostatic or bucket traps with low
pressure steam. On high pressure steam, use bucket traps.
Use thermostatic traps only for air venting.
11 Use bucket traps only with on/off control.
12 Locate traps at least 12 inches below the coil return
connection.
13 If the coils are arranged for series airflow, a separate
control is required on each bank or coil in the direction of
airflow.
14 Do not use modulating steam valves on high pressure
systems.
15 Size modulating valves sized properly. Do not undersize.
16 For freezing conditions or entering air temperatures below
35°F (1.6°C):
a Supply 5 psi steam to coils at all times.
b Thoroughly mix fresh air and return air before it enters
the coil. Locate temperature control elements properly
to obtain true air mixture temperatures.
c As additional protection against freeze-up, install the
trap sufficiently below the coil to provide an adequate
hydrostatic head for removal of condensate during an
interruption in the steam pressure. Estimate three feet
for each 1 psi of trap differential required.
d On startup, admit steam to coil ten minutes before
admitting outdoor air.
e Close fresh air dampers if steam supply pressure falls
below minimum specified.
Installation Guidelines
2 Water supply and water return connections are copper
sweat on units 002 through 010 and male NPT iron pipe on
units 015 through 030.
3 When installing couplings, do not apply undue stress to the
connection extending through unit panel. Use a backup
pipe wrench to avoid breaking the weld between coil
connection and header.
4 Follow recommendations of the control manufacturer
regarding types, sizes, and installation of controls.
5 Hot water coils are not recommended for use with entering
air below 40°F.
6 If fresh air and return air are to be heated by a hot water
coil, take care in the design of the system to provide
thorough mixing before air enters the coil.
Figure 14: Water Heating Coil Connections
One and Two Row Coil
with Spayed Headers
Figure 15: Piping Arrangements
Steam main
Vacuum breaker
1/2" check valve
Figure 13: Steam Coil Connections
RETURN
SUPPLY
Water Heating Coils
Heating coil connection guidelines are listed below. Refer to
Figures 14 and 15.
1 Water supply and water return connections extend through
the end panel of the coil section. All connections are
labeled on the end panel.
12" min.
Return main
McQuay IM 782-2 13
Page 14
Installation Guidelines
Drain Pan Traps
Destiny air handlers have a drain pan connection on both sides
of the unit. Drain connections can be made on either side or
both sides. Drain lines and traps should run full size from the
drain pan connection. Drain pans should have traps to allow
condensate from coils to drain freely. The trap depth and
distance between the trap outlet and the drain pan outlet should
be twice the static pressure in the drain pan section under
normal operation for the trap to remain sealed. See Figure 16.
A secondary drain connection on the drain pan is standard on
all Destiny units. Secondary drain connections are required in
some applications as a visual means of identifying clogged
primary drain lines.
Figure 16: Allow Adequate Distance Between Trap Outlet
and Drain Outlet
Pressure (P)
at the drain pan
2P
2P
Figure 17: Removing the Shipping Bracket, Sizes 002–010
Spring Mount Adjustments—Twin Fan Units
The spring isolators under the four corners of the fan and
motor assembly have been factory adjusted while the fan was
not running. See Table 1. With the unit operating at normal
cfm and static pressure, the isolators should all be at the same
height opening. If adjustments are required, loosen the 5/16"
capscrew on top of the isolator and turn the adjusting bolt to
lower or raise the fan and motor base. Retighten the capscrew
when adjustments are completed. See Figure 18 below.
When seismic snubbers and/or thrust restraints are provided,
no additional adjustments are required.
Note – The door panels on some applications have a close
clearance over the drain pipes. Extend the drain fitting
with a coupling if necessary for door clearance.
Internal Isolation Assembly Adjustment
Units have internally isolated fan and motor assemblies that
are secured with brackets for shipment.
Before Operating the Unit
Remove the shipping bracket and bolts and discard. The
shipping brackets located on the opposite drive side of the unit
are difficult to access from the drive side of the unit. Either
remove them before the unit is assembled, or remove the panel
on the opposite drive side to gain access.
Table 1: Spring Mount Adjustment—Twin Fan Units
Spring mount adjustment at rest, unit sizes 015 to 030 ONLY
Fan discharge
position
1 3.75 3.75 4.25
2 4.25 3.75 4.25
3 4.25 3.75 4.25
4 3.75 3.75 4.25
Figure 18: Spring Mount Adjustments—Twin Fan Units
Dim "H"
POS 3
POS 4
Top or bottom
horizontal H
Motor
Fan
Downblast
H
Spring height
adjustment screw
POS 2
Airflow
POS 1
Upblast
H
Fan isolator position numbers
14 McQuay IM 782-2
Page 15
Installation Guidelines
Electric Heat Section (Optional)
Optional factory installed electric heat section consists of open
coil duct heater mounted to the unit at the supply fan
discharge. Heat section includes heating coils and an electrical
control box with single point field power connection for heater
and supply air fan.
Factory provided field knockouts are located on the side of the
electric heat control panel for field power and control wiring to
pass through. A factory installed non-fused disconnect is
located in the electric heat control panel to disconnect power to
the supply air fan and heater components. All wiring must be
in conformance with the national electric code and local
restrictions.
Open Coil Duct Heater
• Complete with overload and thermal protection
• Includes fan interlock and air flow switch safety protection
• High quality, alloy nichrome wire [80%Ni / 20%Cr]
• High di-electric level ceramic insulators
• Screw terminals
Figure 19: Heater Nomenclature
Single Point Power
• Non-fused disconnect
• Electric heat is factory wired including contactors and fuses
per step and as required by UL
• Fan motor is factory wired including contactor or starter and
fuses as applicable
• Fused control transformer allows the heater and fan to be
sequenced by standard 24 volt thermostat
• Indoor control panel with tool access hinged door houses all
components
Quality Control
• Heaters are di-electrically tested for 1000V plus twice the
rated volts, or 2000V whichever is greater. The resistance of
each heater is measured and recorded and must be within 5%
of the rated value
• Every heater is checked during the production process and
as a final assembly
C M XX - XX - XX
Heater
Modular
Voltage
Figure 20: Destiny Unit with Left Hand Electric Heat
Knockouts: Four Diameters
2.38, 1.62, 1.88, 1.00
Left Hand Electric
Heat Shown
(Right Hand Optional)
3.00
Airflow
Steps
Phases
Wattage
2.25
3.00
Electric Heat Matches
Destiny Fan Discharge
and Attaches Directly
to Destiny Unit
McQuay IM 782-2 15
9.50
Front
Removable Panel
for Full Access
Page 16
Figure 21: Typical 1-Phase Electric Heat Wiring Diagram and Legend
16 McQuay IM 782-2
Page 17
Figure 22: Typical 3-Phase Electric Heat Wiring Diagram and Legend
T1 T2 T3
Installation Guidelines
T1 T2 T3
T1 T2 T3 T1 T2 T3
McQuay IM 782-2 17
Page 18
Electric Heat KW Options
V
V
V
V
Table 2: KW Options by Unit Size
Unit Size
002 003 004 005 007 010
KW Range 1.5 - 10 2.5 - 20 2.5 - 20 4 - 26 6 - 38 6 - 55
Heater Amps
Table 3: Heater Amps
oltagePhase11.5 2 2.533.544.555.566.57
120 1
240 1
240 3
480 3
600 3
8.33 12.50 16.67 20.83 25.00 29.17 33.33 37.50 41.67 45.83 50.00 54.17 58.33
4.17 6.25 8.33 10.42 12.50 14.58 16.67 18.75 20.83 22.92 25.00 27.08 29.17
2.41 3.61 4.82 6.02 7.23 8.43 9.63 10.84 12.04 13.25 14.45 15.66 16.86
1.20 1.81 2.41 3.01 3.61 4.21 4.82 5.42 6.02 6.62 7.23 7.83 8.43
0.96 1.45 1.93 2.41 2.89 3.37 3.85 4.34 4.82 5.30 5.78 6.26 6.74
KW
oltage Phase 7.5 8 8.5 9 10 11 12 13 14 15 16 17
120 1
240 1
240 3
480 3
600 3
oltage Phase 18 19 20 22 24 26 28 30 32 34 36 38
120 1
240 1
240 3
480 3
600 3
oltage Phase 40 45 50 55
120 1
240 1
240 3
480 3
600 3
62.50 66.67 70.83 75.00 83.33 91.67 100.00 108.33 116.67 125.00 133.33 141.67
31.25 33.33 35.42 37.50 41.67 45.83 50.00 54.17 58.33 62.50 66.67 70.83
18.06 19.27 20.47 21.68 24.08 26.49 28.90 31.31 33.72 36.13 38.54 40.94
9.03 9.63 10.24 10.84 12.04 13.25 14.45 15.66 16.86 18.06 19.27 20.47
7.23 7.71 8.19 8.67 9.63 10.60 11.56 12.52 13.49 14.45 15.41 16.38
150.00 158.33 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
75.00 79.17 83.33 91.67 100.00 108.33 116.67 125.00 133.33 141.67 150.00 158.33
43.35 45.76 48.17 52.99 57.80 62.62 67.44 72.25 77.07 81.89 86.71 91.52
21.68 22.88 24.08 26.49 28.90 31.31 33.72 36.13 38.54 40.94 43.35 45.76
17.34 18.30 19.27 21.19 23.12 25.05 26.97 28.90 30.83 32.76 34.68 36.61
KW
N/A N/A N/A N/A
N/A N/A N/A N/A
96.34 108.38 120.42 132.47
48.17 54.19 60.21 66.23
38.54 43.35 48.17 52.99
Electric Heat Safety
KW
KW
Airflow Switch:
Provides the best means of protection against air failure
Overcurrent Protection
Overcurrent fuse protection is provided for each stage of
electric heat (in lieu of one per 48 amperes).
caused by fan belt or other malfunction. Switches are of the
differential pressure, diaphragm-operated type and require a
minimum total pressure differential of .05" WC. The switch is
factory wired in series with the manual reset cutout.
Thermal (Over temperature) Protection
Primary - Automatic limit switches, one per step (120°F or
150°F as appropriate).
Backup - Manual reset thermal cutout (180°F).
Fan Interlock Method:
To prevent the heater from being energized unless the fan is
on, the heater includes two interlock methods: an airflow
switch, and the use of an auxiliary contact in the motor starter
contactor (3ph) or a fan relay (1ph).
18 McQuay IM 782-2
Page 19
Installation Guidelines
Electric Heat Operation
The sampling probe is suitable for left= or tight-hand airflow
and in positive pressure applications may require field
adjustment so the probe faces upstream. This is normally done
during installation by removing two screws, rotating the probe
180° and replacing the screws. Removing the heater from the
duct is not necessary.
The electric heater is designed to operate while installed and
connected to the unit at the supply air fan discharge, to heat air
passing through the heating elements.
Temperature rise is very important and can be obtained using
the following calculation:
Temperature Rise = (KW)(3159)
CFM
Note: Maximum leaving air temperature = 120°F
NOTICE
Heater are furnished for zero clearance between the duct
and combustible surfaces. However, it is not
recommended that any combustible material be allowed
to touch any electric duct heater or immediate
surrounding areas.
NOTICE
Heaters are not intended to be installed with less than 20” of
straight duct at the outlet of the heater.
NOTICE
Field wiring necessary temperatures are:
1) 194°F for dry weather.
2) 167°F for humid weather.
Field Power Wiring
Wiring must comply with all applicable codes and ordinances.
The warranty is voided if wiring is not in accordance with
these specifications. An open fuse or starter indicates a short,
ground, or overload. Before replacing a fuse or resetting a
starter, identify the trouble and correct.
According to the National Electrical Code, a disconnecting
means shall be located within sight of and readily accessible
from the air conditioning equipment. The unit can be ordered
with an optional factory mounted disconnect switch. This
switch is not fused. Power leads must be over-current
protected at the point of distribution. The maximum allowable
overcurrent protection (MROPD) appears on the unit
nameplate.
WARNING
Hazardous voltage. Can cause severe injury or death.
Disconnect electric power before servicing equipment. More
than one disconnect may be required to de-energize the unit.
Supply Power Wiring
1 Allowable voltage tolerances:
a 60 Hertz
– Nameplate 208V: Min. 187V, Max. 229V
– Nameplate 230V: Min. 207V, Max. 253V
– Nameplate 460V: Min. 414V, Max. 506V
– Nameplate 575V: Min. 518V, Max. 633V
b 50 Hertz
– Nameplate 380V: Min. 360V, Max. 418V
2 Minimum Circuit Ampacity (MCA) Calculation is based
on the following formulas:
– Electric heat less than or equal to 50 kW
MCA = 1.25 (heater FLA + largest motor loads) +
(the rest of the loads)
– Electric heat greater than or equal to 50 kW
MCA = 1.25 (largest motor load) + (the rest of the
loads) + heater FLA
3 Size wires in accordance with Table 310-16 or 310-19 of
the National Electrical Code.
4 Wires should be sized for a maximum of 3% voltage drop.
Electrical Installation
1 Electrical service to the fan must correspond to the rated
voltage on the motor nameplate and be in conformance
with the National Electric Code and local restrictions.
2 The fan section metal frame must be connected to the
building electrical ground.
3 A door electrical interlock is not provided as standard.
4 Thermal motor protection is external to the unit. Unless the
unit is provided with a variable frequency drive, thermal
protection and a disconnect switch provision per electric
codes are provided by others.
McQuay IM 782-2 19
Page 20
Operation Guidelines
Operation Guidelines
Startup Checks
When performing startup and service, always take thorough
safety precautions. Start-up functions must be performed by
trained, experienced personnel.
WARNING
ROTATING FAN
Can cause severe injury or death. Before servicing fans,
lockout and tag out power.
AVERTISSEMENT
PIÈCES MOBILES DANGEREUSES
Avant de réparer ou entretenir les ventilateurs, coupez
l’alimentation èlectrique de cet appareil et bloquez le
commutateur à OFF.
WARNING
FIRE/ELECTRIC SHOCK HAZARD
Can cause property damage, personal injury or death. Wire
fan power supply and ground motor frame in accordance with
local electric codes.
AVERTISSEMENT
Risques d’incendie et d’électrocution pouvant causer des
dommages matériels, des blessures et même la mort.
L’alimentation électrique du moteur du ventilateur de même
que la mise à la terre du chàssis du moteur doivent être faits
conformément aux codes d’installations électriques en
vigueur.
WARNING
FAN MOTOR REQUIRES OVERLOAD PROTECTION.
Failure to provide motor overload protection can result in fire,
property damage, electric shock, personal injury or death.
Connect motor to an overload protective device rated in
compliance with local electric codes.
CAUTION
DO NOT OVERHEAT FAN MOTOR
High air temperatures in the fan section can cause the fan
motor to burnout. On draw-through air handlers or air handlers
with the fan section down the air stream from the heating
section, the discharge air temperature of the heating section
must not exceed 104°F (40°C).
ATTENTION
Risques de dommages dans le moteur du ventilateur
électrique. Si Ia température de l’air a proximité du
ventilateurest élevée, le moteurdu ventilateur électrique peut
chauffer et brûler. Sur les transmetteurs d’air à circulation
transversale ou les transmetteurs dont le ventilateur est en
aval de l’unité de chauffage, régler la température de l’air
sortant de l’unité de chauffage à 40°C (104°F).
Before starting the unit:
Make sure that fan electrical power source is disconnected and
locked in the OFF position before entering fan section.
1 With ductwork connected, check the unit for complete and
proper installation.
2 Check that all construction debris is removed and filters are
clean.
3 Check that all electrical work is complete and properly
terminated. Check that all electrical connections are tight
and that the proper voltage is connected. Phase imbalance
must not exceed 2%.
4 Ball bearings on fan shaft and motor are prelubricated and
do not need grease before startup.
5 Check tightness of setscrews in bearings and fan wheel(s).
If retightening is needed, make certain the fan wheel(s) are
aligned properly or setscrews are torqued per Table 2 on
page 21.
AVERTISSEMENT
Risques d’incendie et d’électrocution pouvant causer des
dommages matériels, des blessures et même la mort.
Connecter au moteur du ventilateur électrique un dispositif de
protection contre les surcharges conforme aux codes
d'installations électriques en vigueur.
20 McQuay IM 782-2
Equipment damage due to loose fasteners represents
improper start-up and equipment abuse. It is not covered by
the warranty.
Des dommages causés à l’unité dû à des attaches mal
serrées signifie que le démarrage a été inadéquat et
constitue un usage abusif de l’équipement. Ceci n’est pas
couvert par la garantie.
CAUTION
ATTENTION
Page 21
6
Check alignment of fan and motor sheaves and belt tension.
Adjust if necessary. Check tightness of sheave setscrews
and/or capscrews. See Figure 26 and Figure 27 on page 25
and Figure 28 on page 26.
7 Leak test the thermal system to verify that connections are
tight.
8 Check that condensate drain is trapped.
9 Rotate shaft by hand to be sure it is free.
10 Fan startup: Fan should start and run. Observe the rotation.
If the fan is operating backward, reverse two legs of the
three-phase supply power.
Note – Variable pitch fan drives are usually provided for
operation in the mid-speed adjustment range. However,
the drives usually ship with the adjustment opened for
minimum fan speed. Adjust the drives for the proper
airflow. See “Fan Drive Adjustments” on page 22.
After first 48 hours of operation:
1 Disconnect and lockout electrical power source.
2 Check tightness of all bearing, wheel, and sheave setscrews
(or capscrews). See Table 3.
3 Recheck belt tension and adjust if necessary. Belts
tensioned sufficiently to slip one to two seconds at startup
will perform satisfactorily, extending life and reducing
vibration. If retensioning is necessary, be certain to retain
sheave alignment.
Table 4: Bearing Collar and Wheel Hub Setscrew Torque
Setscrew Minimum torque
Diameter (inches) ft / lbs kg / M
1/4 5.5 .76
1/16 10.5 1.45
3/8 19.0 2.63
7/16 29.0 4.01
Operation Guidelines
Operating Limits
Do not exceed the operating limits in Table 5. A fan wheel that
is operated beyond the rpm and temperature limits shown may
suffer permanent distortion or fracture. The resulting
unbalance may cause severe unit vibration.
Table 5: Fan Operating Limits
Forward curved—housed
Twin
Twi n
Diameter 7 × 7 9 × 9 10 × 10 12 × 12
Maximum
rpm
2680 2650 2100 1700 2100 1700 1500
10"
12"
Twi n
15"
Fan Vibration Levels
Each unit as shipped is trim balanced to operate smoothly. To
provide satisfactory operation after shipping and installation,
use the accepted industry guidelines for field balancing fans.
Vibration ≤ 0.20 in/sec.
Note – Excessive vibration from any cause contributes to
premature fan and motor bearing failure. Monitor overall
vibration levels every six months of operation. An
increase in levels is an indication of potential trouble.
Vibration Causes
1 Wheel imbalance
a Dirt or debris on wheel blades
b Loose setscrews in wheel hub or bearing-to-shaft
c Wheel distorted from overspeed
2 Bent shaft
3 Drive faulty
a Variable pitch sheaves—Axial and radial runout of
flanges, uneven groove spacing, out of balance. Also
similar faults in driven sheave.
b Bad V-belts, lumpy or mismatched, belt tension too tight
or too loose
4 Bad bearings, loose bearing hold-down bolts
5 Motor imbalance
6 Fan section not supported evenly on foundation
McQuay IM 782-2 21
Page 22
Service and Maintenance
Service and Maintenance
Periodic Service and Maintenance
1 Check all moving parts for wear every six months.
2 Check bearing collar, sheave, and wheel hub setscrews,
sheave capscrews, and bearing hold-down bolts for
tightness every six months.
Ball Bearing Lubrication
1 Motor bearings—All ball bearings are prelubricated and do
not require additional grease during installation. However,
periodic cleaning out and renewal of grease is necessary.
Exercise extreme care when cleaning to prevent foreign
matter from entering the bearing. It is also important to
avoid over greasing. Only use a high grade, clean mineral
grease with the following characteristics.
a Melting point preferably over 302°F (150°C).
b Does not separate by oil and soap under operating and
storage conditions.
c Free of abrasive matter, acid, alkali, and moisture.
Specific greasing instructions are located on a label
attached to the fan section door.
2 Fan shaft bearings—All ball bearings are prelubricated and
do not require additional grease during installation.
Periodic greasing is necessary. Bearings are accessible in
the fan section. A grease fitting is located on each side of
the fan shaft. Do not over lubricate. Wipe off any excess
grease to prevent overheating. The lubrication interval
varies with the period of operation and temperature of the
ambient air. Use the guidelines in the table below:
Table 6: Bearing Operating Temperature Range
Bearing operating temperature range
To 130°F
(54°C)
Continuous operation 6 months 4 months 2 months
12-hr/day operation 12 months 12 months 6 months
Figure 23: Fan Shaft Bearing Grease Fitting
To 150°F
(66°C)
Grease
fitting
(one each side
of fan shaft)
Over 150°F
(66°C)
Table 7: Lubricants Recommended for Fan Shaft Ball
Bearings
Manufacturer
Texaco Lubricants Company Premium RB –30 to 300 –34 to 149
Keystone Ind. Lubricants 81EP-2 0 to 250 –18 to 121
Mobil Oil Corporation
Chevron U.S.A. Inc. SRI-2 –20 to 325 –29 to 163
Exxon Company, U.S.A. Ronex MP –40 to 300 –40 to 149
Shell Oil Company Alvania No. 2 –20 to 240 –29 to 116
Note: Temperature ranges over 225°F are shown for lubricants only. High
temperature applications are not suitable for standard air handler
components.
Product
name
Mobilith
SCH100
Temperature range
°F °C
–40 to 350 –40 to 177
Fan Drive Adjustments
WARNING
ROTATING FAN
Can cause severe injury or death. Before servicing fans,
lockout and tag out power.
Do not open the hinged access door and access panels while
the unit is operating. Moving parts and strong suction forces
can cause severe personal injury or death.
Before entering any fan section, make sure the electrical
power source to the fan motor is disconnected, locked out and
tagged out.
AVERTISSEMENT
PIÈCES MOBILES DANGEREUSES.
Avant de réparer ou entretenir les ventilateurs, coupez
l’alimentation èlectrique de cet appareil et bloquez le
commutateur à OFF.
Upon completion of the air balance, replace the variable
pitched motor sheave with a properly sized, fixed sheave. A
matching fixed sheave provides longer belt and bearing life
and vibration-free operation. Initially, it is best to have a
variable pitched motor sheave for the purpose of air balancing.
Once the balance is achieved, fixed sheaves maintain
balancing and alignment more effectively. Replace the
adjustable sheaves with fixed sheaves.
With the electrical power disconnected, locked and tagged out,
measure the diameter of the V-belt outer surface where it
passes around the sheave (pitch diameter). Calculate fan speed
from the motor nameplate rpm.
Fan rpm = Motor rpm ×
Measured diameter at motor sheave
Measured diameter at fan sheave
22 McQuay IM 782-2
Page 23
Service and Maintenance
VM and VP Variable Pitch Key Type Sheaves
Mounting:
1 Mount all sheaves on the motor or driving shaft with the
setscrews
2 Verify that both driving and driven sheaves are in
A toward the motor.
alignment and that shafts are parallel.
3 Fit internal key D between sheave and shaft and lock
setscrew
Adjusting:
1 Loosen setscrews B and C in moving parts of sheave and
pull out external key
A securely in place.
E. (This key projects a small amount
to provide a grip for removing.)
2 Adjust sheave pitch diameter for desired speed by opening
moving parts by half or full turns from closed position.
Do not open more than five full turns for
full turns for
3 Replace external key E and securely tighten setscrews B
over key and setscrews
B belts.
C into keyway in fixed half of the
A belts or six
sheave.
4 Put on belts and adjust belt tension.
Do not force belts over grooves. See “Fan Drive Belt
Adjustment” on page 26.
5 Make future adjustments by loosening the belt tension and
increasing or decreasing the pitch diameter of the sheave by
half or full turns as required. Readjust belt tension before
starting drive.
6 Adjust both halves of two-groove sheaves the same number
of turns from closed position to provide the same pitch
diameter.
7 Verify that all keys are in place and that all setscrews are
tight before starting drive. Check setscrews and belt tension
after 24 hours service.
Figure 24: VP Type Sheave Adjustment
A
Single groove
B
A
Two groove
C
Note: Do not operate sheave with flange
projecting beyond the hub end.
B
E
D
C
Key E projects
to provide a grip
for removal.
B
E
D
C
LVP Variable Speed Sheaves
Mounting:
Slide sheave on motor shaft so that the side of the sheave
1
with setscrew
A is next to the motor, when setscrew A is in
the hub or barrel of the sheave.
2 When setscrew A is at an angle in the center flange B,
mount it away from the motor so the outer locking ring and
flange can be removed to get to the setscrew.
3 To remove the flange and locking ring:
a Loosen setscrews D.
b Loosen but do not remove capscrews E.
c Remove key F. (This key projects a small amount to
provide a grip for removing.)
d Rotate the flange counterclockwise until it disengages
the threads on the sheave barrel.
4 Verify that the driving and driven sheaves are in alignment
and the shafts are parallel. When aligning two-groove
sheaves, allow room between the sheave and motor to get
to capscrews
5 Insert key C between the sheave and the shaft and tighten
setscrew
6 If flange and locking ring have been removed, when
E.
A securely.
replacing them make sure that the inner and outer flanges
are open from the closed position by the same amount as
the other flange. Determine this by accurately measuring
the top width of the grooves.
McQuay IM 782-2 23
Page 24
Service and Maintenance
7
Insert key F.
8 Tighten setscrews D and capscrews E.
9 Put on belts and adjust belt tension. Do not force belts
over grooves. See “Fan Drive Belt Adjustment” on page
26.
10 Be sure that all keys are in place and all setscrews and all
capscrews are tight before starting the drive. Check and
retighten all screws and retension belts after approximately
24 hours of service.
Adjusting:
1 Slack off belt tension if belts have been installed.
2 Loosen setscrews D.
3 Loosen but do not remove capscrews E.
4 Remove key F. (This key projects out a small amount to
provide a grip for removing.)
Figure 25: LVP Type Sheave Adjustment
A
A
5 Adjust pitch diameter by opening or closing the movable
flanges by half or full turns. (Two-groove sheaves are
supplied with both grooves set at the same pitch diameter.)
Move both movable flanges the same number of turns
to provide the same pitch diameter for satisfactory
operation. Do not open sheaves more than five turns for
A belts or six turns for B belts.
6 Replace key F.
7 Tighten setscrews D and capscrews E.
8 If belts have been installed, readjust belt tension. If belts
have not been installed, install them and adjust belt tension.
Do not force belts over grooves See “Fan Drive Belt
Adjustment” on page 26.
9 Verify that all keys are in place and all setscrews and all
capscrews are tight before starting the drive. Check and
retighten all screws and retension belts after approximately
24 hours of operation.
A
E
C
F
D
E
D
B
Section A-A Section A-A
E
C
A
F
D
24 McQuay IM 782-2
Page 25
MVP Variable Speed Sheaves
e
Mounting:
1 Verify that both driving and driven sheaves are in
alignment and the shafts are parallel. The centerline of the
driving sheave must be in line with the centerline of the
driven sheave. See Figure 27.
2 Before starting drive, verify that all setscrews are torqued
to the values shown in Table 26. Check setscrew torque
and belt tension after 24 hours of service.
Adjusting:
1 Adjust motor base forward to release belt tension. For
6 Before operating the drive, tighten BOTH locking screws
A in the outer locking ring. Use a torque wrench and
tighten to the value shown in Table 26.
7 Replace belts and adjust the motor base to tension the belts
properly. See “Fan Drive Belt Adjustment” on page 26.
8 Do not loosen any screws other than the two locking
screws
A in the outer locking ring when adjusting the
sheave pitch. Do not operate the drive until the locking
screws are set to the torque specifications.
Figure 26: Sheave Adjustment
Must be
parallel
easier adjustment, remove the belts.
2 Loosen, but do not remove both of the locking setscrews A
in the outer locking ring by using a hex key or torque
wrench with a hex bit.
3 Adjust sheave to desired pitch diameter by turning the
outer locking ring. Use a spanner wrench or drift inserted
into the three holes that are located 120° apart on the ring.
4 Any pitch diameter can be obtained within the sheave
Bearing
Motor
Center lines
must coincid
range. One complete turn of the outer locking ring changes
the pitch diameter 0.233".
5 Do not open sheaves more than the following amounts:
• Do not open
belts or 6 turns for the
• Do not open
• Do not open
• Do not open
Table 8: Screw Torque Values
Nominal screw size
(dia-thds/in)
1/4-20NC 150 12.5 100 87 7.3 3/16 50
5/16-11NC 305 25.4 200 165 13.8 1/4 90
3/8-16NC 545 45.4 350 290 24.2 1/4, 5/16 150, 250
1/2-13NC 1300 108.3 N/A 620 51.7 N/A N/A
5/8-11NC N/A N/A N/A 1225 102.1 N/A N/A
Figure 27: Sheave Adjustment
B sheaves more than 4 3/4 turns for the A
B belts.
C sheaves more than 9 1/2 turns.
5V sheaves more than 6 turns.
Must be
parallel
Adjustable
sheave
8V sheaves more than 8 turns.
Socket head
cap screws
Seating torque Seating torque Seating torque Seating torque Length (L) Seating torque
(in-lbs) (ft-lbs) (in-lbs) (in-lbs) (ft-lbs) (in) (in-lbs)
Flat head socket
screws
Adjustable
center-flange
Lengths equal or greater than diameter For lengths (L) less than diameter
Fixed
center-flange
Hollow head setscrews only
(2) Locking
set screws A
Flathead socket screws
(Do not remove.)
Split taper
bushing
Capscrews
(Do not remove.)
Stationary
end-flange
Outer
locking-ring
Inner locking-ring
(3) Holes for
spanner w rench
or drift
McQuay IM 782-2 25
Page 26
Fan Drive Belt Adjustment
General Rules of Tensioning
1 The ideal tension is the lowest tension at which the belt
does not slip under peak load conditions.
2 Check tension frequently during the first 24 to 48 hours of
operation.
3 Over tensioning shortens belt and bearing life.
4 Keep belts free from foreign material, which may cause
slippage.
5 Make V-drive inspection on a periodic basis. Adjust
tension if the belt is slipping. Do not apply belt dressing.
This may damage the belt and cause early failure.
Tension Measurement Procedure
1 Measure the belt span. See Figure 28.
2 Place belt tension checker squarely on one belt at the
center of the belt span. Apply force to the checker,
perpendicular to the belt span, until the belt deflection
equals belt span distance divided by 64. Determine force
applied while in this position.
3 Compare this force to the values in Table 9 on page 27.
4
Adjust to the minimum value. If the belts slip, add tension.
Figure 28: Drive Belt Adjustment
Deflection =
Belt span
64
WARNING
Moving belt and fan can cause severe personal injury or death.
During installation and filter maintenance:
• Lock and tag out fans to prevent accidental start up.
• Do not enter the filter compartment until the fan is
completely stopped.
• Use approved equipment for reaching filters located above
normal reach. Do not step on filter frames or unit
components.
• Floor surfaces must be dry and free of oil or grease.
AVERTISSEMENT
Pendant l’installation et où l’entretien des filtres, une courroie
en mouvement ou un ventilateur en opération peuvent causer
des blessures graves où même causer la mort.
• Verouiller les démarreurs des ventilateurs et afficher un
avis de mise-en-garde afin de prévenir tout accident ou
démarrage.
• Attendre que le ventilateur soit complètement arrêté avant
d’entrer dans l’unité.
• Utiliser seulement des équipements approuvé pour joindre
les bancs de filtres; ne pas mettre soit sur les cadres des
filtres ou même sur toutes composantes de l’unité.
• La surface des planchers doit être sec et libre de toute
trace d’huile et où de graisse.
B
e
l
t
p
s
a
n
26 McQuay IM 782-2
Page 27
Table 9: Belt Deflection Force
Sheave diameter (inches) Deflection force (lbs)/belt deflection force
Cross section
A, AX
B, BX
5V, 5VX
Smallest sheave
diameter range
3.0 to 3.6
3.8 to 4.8
5.0 to 7.0
3.4 to 4.2
4.4 to 5.6
5.8 to 8.6
4.4 to 6.7
7.1 to 10.9
11.8 to 16.0
rpm range
1000 to 2500 2.8 5.5 3.0 6.1
2501 to 4000 2.1 4.2 2.5 5.0
1000 to 2500 3.4 6.8 3.7 7.4
2501 to 4000 2.4 5.7 3.2 6.4
1000 to 2500 4.0 8.0 4.7 9.4
2501 to 4000 3.5 7.0 3.8 7.6
850 to 2500 — — 3.6 7.2
2501 to 4000 — — 3.1 6.2
860 to 2500 4.0 7.9 5.2 10.5
2501 to 4000 3.3 6.7 4.5 9.1
860 to 2500 4.7 9.4 6.3 12.6
2501 to 4000 4.5 8.9 5.4 10.9
500 to 1749 — — 7.6 15.2
1750 to 3000 — — 6.6 13.2
3001 to 4000 — — 4.2 8.5
500 to 1740 9.5 18.9 11.0 22.1
1741 to 3000 8.3 16.7 10.0 20.1
500 to 1740 11.7 23.4 12.7 25.5
1741 to 3000 10.5 21.8 12.5 25.0
Cross section A, B, 5V Cross section AX, BX, 5VX
Min Max Min Max
Page 28
Service and Maintenance
Coil Maintenance
CAUTION
SHARP EDGES AND COIL SURFACES
are a potential injury hazard. Avoid contact with them.
ATTENTION
Les bords tranchants et les surfaces des bobines sont un
risque de blessure. Ne les touchez pas.
1 For maximum performance, the coil must be clean. Check
once a year under normal operating conditions and brush or
vacuum clean if necessary. Use a chemical coil cleaner on
multiple row coils. Read and follow the chemical cleaner’s
instructions since some cleaners may contain harsh
chemicals. Take care not to damage fins while cleaning.
2 Drain pans in any air conditioning unit may have some
moisture. Algae and other organisms can grow due to
airborne spores and bacteria. Clean periodically to prevent
build-up from plugging the drain and causing the drain pan
to overflow. Keep drain pans clean to prevent the spread of
disease. Cleaning should be performed by qualified
personnel.
3 Dirt and lint can clog the condensate drain, especially with
dirty filters. Inspect twice a year to help avoid overflow.
WARNING
Clean drain pan regularly so mold does not develop.
If fan replacement is required, the entire fan assembly can be
pulled out the side of the cabinet. The fan assembly includes
the fan housing, the bearing support, and the fan base.
1 To remove the fan assembly, remove the side panels
(follow instructions for side panel removal).
2 Disconnect the neoprene bulkhead seal that is attached to
the fan discharge. Then disconnect the fan sled from each
of the corner mounts and pull the entire assembly out the
side of the unit.
3 Loosen the fan bearings and pull out the shaft. Disconnect
the fan housing from the fan sled and bearing support by
removing the attaching bolts.
4 Replace the new fan, reconnect the shaft and bearings and
put the fan assembly in the cabinet. Replace panels and
fasteners.
Coil Removal and Replacement
Before removing the coil, disconnect all piping.
1 Remove exterior panels from both sides of the coil section.
Remove screws that secure the top of the leaving coil face
to the upper track on the inside top of the unit.
2 Lift drain pan condensate connection above the unit frame
flange and slide drain pan, coil(s), and baffles out of unit.
3 Slide the coil, blockoffs, and drain pan assembly back into
unit the same way it was removed. Check the installation
for an airtight fit.
4 Reinstall screws that secure the top of the leaving coil face
to the upper track on the inside top of the unit.
AVERTISSEMENT
Pour eviter la moisissure Nettoyer regulierement le bassin de
recuperage.
Component Removal and Replacement
Panel Removal
Remove the screws located along the sides of the panel. Pull
the panel out using the pocket pull handles. If the panel does
not have a pull handle, remove the adjacent panel with a
pocket pull or door and pop out the panel from the inside.
Fan Section Removal
The fan shaft, motor, and any drive components are removable
through the access door or panel opening.
Figure 29: Coil Removal
Remove screws
1
from the upper track
that hold coil/drain pan
in place.
Airflow
Lift drain pan connection
2
up and slide coil/drain pan
assembly out.
28 McQuay IM 782-2
Page 29
Warranty
Warranty
Consult your local McQuay Representative for warranty
details. Refer to Form 933- 430285Y. To find your local
McQuay Representative, go to www.mcquay.com.
Warranty Return Material Procedure
Defective material may not be returned without permission of
authorized factory service personnel of McQuay International
in Minneapolis, Minnesota, (763) 553-5330. A “Return
Goods” tag must be included with the returned material. Enter
the required information to expedite handling and prompt
issuance of credits. All parts must be returned to the
appropriate McQuay facility, designated on the “Return
Goods” tag. Transportation charges must be prepaid.
The return of the part does not constitute an order for
replacement. Therefore, a purchase order must be entered
through the nearest McQuay representative. The order should
include part number, model number, and serial number of the
unit involved.
Credit will be issued on customer’s purchase order following
an inspection of the return part and upon determination that the
failure is due to faulty material or workmanship during the
warranty period.
Replacement Parts
When writing to McQuay for service or replacement parts,
refer to the model number and serial number of the unit
stamped on the serial plate attached to the unit. If replacement
parts are required, mention the date of installation of the unit
and date of failure, along with an explanation of the
malfunctions and a description of the replacement parts
required.
McQuay IM 782-2 29
Page 30
McQuay Training and Development
Now that you have made an investment in modern, efficient McQuay equipment, its care should be a high priority.
For training information on all McQuay HVAC products, please visit us at www.mcquay.com and click on training, or
call 540-248-9646 and ask for the Training Department.
Warranty
All McQuay equipment is sold pursuant to its standard terms and conditions of sale, including Limited Product
Warranty. Consult your local McQuay Representative for warranty details. Refer to Form 933-43285Y. To find your
local McQuay Representative, go to www.mcquay.com.
This document contains the most current product information as of this printing. For the most up-to-date product
information, please go to www.mcquay.com.
© 2007 McQuay International • www.mcquay.com • 800-432-1342
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