Modine Manufacturing MPR Installation And Service Manual

MCP15-500.7

5H0816400000

March, 2018

INSTALLATION AND SERVICE MANUAL

commercial packaged ventilation system units

model MPR

Model MPR Commercial Packaged Ventilation
System Unit (C-Cabinet size shown)

Improper installation, adjustment, alteration,
service or maintenance can cause property
damage, injury or death, and could cause
exposure to substances which have been
determined by various state agencies to cause
cancer, birth defects or other reproductive
harm. Read the installation, operating and
maintenance instructions thoroughly before
installing or servicing this equipment.

This unit contains R-410A high pressure
refrigerant. Hazards exist that could result in
personal injury or death. Installation,
maintenance, and service must only be
performed by an HVAC technician qualified in
R-410A refrigerant and using proper tools and
equipment. Due to much higher pressure of
R-410A refrigerant, DO NOT USE service
equipment or tools designed for refrigerants
other than R410A.

WARNING

WARNING

(for units with 24 digit model numbers)

FIRE OR EXPLOSION HAZARD

Failure to follow safety warnings exactly could
result in serious injury, death or property
damage.

Be sure to read and understand the installation,
operation and service instructions in this manual.

Improper installation, adjustment, alteration,
service or maintenance can cause serious
injury, death or property damage.

Do not store or use gasoline or other
flammable vapors and liquids in the vicinity
of this or any other appliance.

WHAT TO DO IF YOU SMELL GAS:

• Do not try to light any appliance.

• Do not touch any electrical switch, do
not use any phone in your building.

• Leave the building immediately.

• Immediately call your gas supplier from
a phone remote from the building.
Follow the gas supplier’s instructions.

• If you cannot reach your gas supplier,
call the fire department.

Installation and service must be performed by
a qualified installer, service agency or the gas
supplier.

Inspection on Arrival

1. Inspect unit upon arrival. In case of damage, report it
immediately to transportation company and your local
factory sales representative.

2.

Check rating plate on unit to verify that power supply meets

available electric power at the point of installation.

3. Inspect unit upon arrival for conformance with description
of product ordered (including specifications where
applicable).

WARNING

THIS MANUAL IS THE PROPERTY OF THE OWNER.

PLEASE BE SURE TO LEAVE IT WITH THE OWNER WHEN YOU LEAVE THE JOB.

1MCP15-500.7

SPECIAL PRECAUTIONS

SPECIAL PRECAUTIONS

THE INSTALLATION AND MAINTENANCE INSTRUCTIONS IN
THIS MANUAL MUST BE FOLLOWED TO PROVIDE SAFE,
EFFICIENT AND TROUBLE-FREE OPERATION. IN ADDITION,
PARTICULAR CARE MUST BE EXERCISED REGARDING
THE SPECIAL PRECAUTIONS LISTED BELOW. FAILURE
TO PROPERLY ADDRESS THESE CRITICAL AREAS COULD
RESULT IN PROPERTY DAMAGE OR LOSS, PERSONAL
INJURY, OR DEATH. THESE INSTRUCTIONS ARE SUBJECT
TO ANY MORE RESTRICTIVE LOCAL OR NATIONAL CODES.

HAZARD INTENSITY LEVELS

1. DANGER: Indicates an imminently hazardous situation
which, if not avoided, WILL result in death or serious injury.

2. WARNING: Indicates a potentially hazardous situation
which, if not avoided, COULD result in death or serious injury.

3. CAUTION: Indicates a potentially hazardous situation
which, if not avoided, MAY result in minor or moderate injury.

4. IMPORTANT: Indicates a situation which, if not avoided,
MAY result in a potential safety concern.

dANGeR

Appliances must not be installed where they may be exposed
to a potentially explosive or flammable atmosphere.

WARNING

de-energized.

11. This unit contains R-410A high pressure refrigerant.
Hazards exist that could result in personal injury or
death. Installation, maintenance, and service must only
be performed by an HVAC technician qualified in R-410A
refrigerant and using proper tools and equipment. Due
to much higher pressure of R-410A refrigerant, DO NOT
USE service equipment or tools designed for refrigerants
other than R410A.

12. The power supply wiring for the Energy Recovery
Section comes from a single point power connection on
the unit. Disconnect power supply at model MPR before
making wiring connections to prevent electrical shock
and equipment damage.

13. When servicing or repairing this equipment, use only
factory-approved service replacement parts. A complete
replacement parts list may be obtained by contacting
Modine Manufacturing Company. Refer to the rating
plate on the appliance for complete appliance model
number, serial number, and company address. Any
substitution of parts or controls not approved by the
factory will be at the owner's risk.

WARNING

1. Failure to follow proper lifting instructions could result in
property damage, serious injury, or death. Lifting should
only be done by a qualified rigging company. Use ALL
lifting points. Test lift to ensure proper balance and
rigging. Never lift in high winds.

2. Disconnect power supply before making wiring
connections or working on this equipment. Follow all
applicable safety procedures to prevent accidental
power up. Failure to do so can result in injury or death
from electrical shock or moving parts and may cause
equipment damage.

3. For units equipped for dual power supply sources, both
sources of power must be disconnected to prevent
electrical shock and equipment damage.

4. All appliances must be wired strictly in accordance with
the wiring diagram furnished with the appliance. Any
wiring different from the wiring diagram could result in a
hazard to persons and property.

5. Any original factory wiring that requires replacement
must be replaced with wiring material having a
temperature rating of at least 105°C.

6. Ensure that the supply voltage to the appliance, as
indicated on the serial plate, is not 5% greater than the
rated voltage.

7. All field gas piping must be pressure/leak tested prior to
operation. Never use an open flame. Use a soap solution or
equivalent for testing.

8. Gas pressure to appliance controls must never exceed
14" W.C. (1/2 psi).

9. To reduce the opportunity for condensation, the minimum
sea level gas input to the appliance, as indicated on the
serial plate, must not be less than 5% below the rated
input, or 5% below the minimum rated input of dual rated
units.

10. When the dead front disconnect switch(es) (for main
unit and/or powered convenience outlet option) is in the
“OFF” position, supply power remains energized at the
line (supply) side of the dead front disconnect switch(es).
The switch body is located inside of another junction
box to protect against contact with the live wiring.
The junction box must not be disassembled unless
the main power supply from the building to the unit is

CAUtIoN

1. Appliances are designed for outdoor installation only.
DO NOT LOCATE APPLIANCES INDOORS.

2. Ensure that the supply voltage to the appliance, as
indicated on the serial plate, is not 5% less than the
rated voltage.

3. Purging of air from gas lines should be performed as
described in ANSI Z223.1 - latest edition “National Fuel
Gas Code”, or in Canada in CAN/CGA-B149 codes.

4. Units not approved for use in potable water systems.

5. Do not operate the unit with steam. The coil is not
designed for steam condensate removal which can
damage the unit.

6. Hot water supplied to the hot water heating option must
not exceed 180°F temperature or 75 PSIG pressure.

7. When servicing the unit, some components may be hot
enough to cause pain or injury. Allow time for cooling of
hot components before servicing.

8. Do not overcharge the refrigeration system. This can
lead to elevated compressor discharge pressure and
possibly flooding the compressor with liquid. This may
result in compressor failure not covered under warranty.

9. Do not reuse any mechanical or electrical component
which has been wet. Such components must be
replaced.

IMPoRtANt

1. To prevent premature heat exchanger failure, do
not locate ANY gas-fired appliances in areas where
corrosive vapors (i.e. chlorinated, halogenated or acid)
are present in the atmosphere.

2. A properly designed drain with trap must be installed
immediately after the unit evaporator coil condensate
drain pan connection. Failure to do so will result in
condensate that cannot properly drain from the unit,

2 MCP15-500.7

TABLE OF CONTENTS / SI (METRIC) CONVERSION FACTORS / UNIT LOCATION

TABLE OF CONTENTS

IMPoRtANt

eventually causing the drain pan to fill. To prevent
damage to the building or unit, a drain pan float switch
is included as standard and will disable the unit if the
maximum condensate level is reached.

3. To prevent premature heat exchanger failure, the input
to the appliance, as indicated on the serial plate, must
not exceed the rated input by more than 5%.

4. To prevent premature heat exchanger failure, check to
be sure the blower has been set to deliver the proper
airflow for the application. Refer to page 17 for Blower
Adjustments.

5. Start-up and adjustment procedures must be performed
by a qualified service agency.

6. All scroll compressors requires the correct supply power
phase rotation. Phase reversal may result in compressor
failure not covered under warranty. Refer to the Start-Up
Procedure section.

7. All refrigeration checks must be made by a qualified
R-410A refrigeration technician.

8. Do not release refrigerant to the atmosphere. When
adding or removing refrigerant, all national, state/
province, and local laws must be followed.

9. On units with the electric preheat option, to prevent
premature heat exchanger failure, check to be sure the
blower has been set to deliver the proper airflow for the
application. Refer to page 17 for Blower Adjustments.

10. The exhaust fan is not designed for high temperature
or smoke control exhaust applications. Exhaust air
temperature must not exceed 104°F. Operating the
exhaust fan above 104°F will result in failure of the
exhaust fan.

SI (METRIC) CONVERSION FACTORS

To Convert Multiply By To Obtain

"W.C. 0.24 kPa
psig 6.893 kPa
°F (°F-32) x 0.555 °C
inches 25.4 mm
feet 0.305 meters
CFM 0.028 m

3

Special Design Requests

Modine Manufacturing Company will sometimes build units
with special features as requested by the customer. This
manual only covers standard features and does not include any
changes made for special feature requests by the customer.
Units built with special features are noted with an SPO (Special
Product Order) Number on the Serial Plate

To Convert Multiply By To Obtain

CFH 1.699 m

3

0.0374 mJ/m

Btu/ft
pound 0.453 kg
Btu/hr 0.000293 kW
gallons 3.785 liters
psig 27.7 "W.C.

/min

3

/min

3

Inspection on Arrival ............................................................ 1

Special Precautions ............................................................. 2

SI (Metric) Conversion Factors ........................................... 3

Special Design Requests .................................................... 3

Storage Prior to Installation ................................................. 3

Unit Location ....................................................................... 4

Installation ......................................................................4-15

Combustible Material and Service Clearances .........4-5

Roof Curb Installation ................................................... 4

General Rigging Instructions/Unit Installation ...........6-7

Duct & Condensate Drain Installation .......................... 8

Electrical Connections .................................................. 9

Gas Connections ........................................................ 10

Vent Terminals and Combustion Air Hoods ................ 11

Gas Heating Option Condensate Drains & Traps ......14

Hot Water Piping Connections ...................................15

Start-Up Procedure ......................................................16-29

General. ...................................................................... 16

Blower Adjustments .................................................... 17

Airflow Proving Switch and Dirty Filter Switch............ 19

Variable Air Movement Applications ........................... 19

Checking Refrigerant Charge ..................................... 20

Gas Heating Option .................................................... 21

Energy Recovery Option (B-Cabinet units only) ........ 28

Unit Features/Options Location Drawings .................... 30-35

Dimensions/Weights .................................................... 36-44

B-Cabinet Size Unit without Energy Recovery. .......... 36

B-Cabinet Size Unit with Energy Recovery. ............... 38

C-Cabinet Size Unit .................................................... 40

D-Cabinet Size Unit .................................................... 42

Base Model Weights ...................................................44

Option and Accessory Pressure Drop Tables ..............45-47

Maintenance .................................................................48-50

Service & Troubleshooting ...........................................51-55

Serial Plates ...................................................................... 56

Model Nomenclature ....................................................57-59

Commercial Warranty ...........................................Back Page

Storage Prior to Installation

If the unit is stored outside prior to installation, the unit should
be covered.

3MCP15-500.7

*Available as a factory
supplied, field installed
accessory.

Curb Gasketing*

2 x 4 Wooden
Nailing Strip*

Curb*

2” Acoustic

Fiberglass

(By Others)

Roof Deck

6” Inverted Channel

(Both Sides)

(By Others)

Roof

Trusses

Cant Strip

(By Others)

Roof Insulation

(By Others)

Counterflashing

(By Others)

Roofing Material

(By Others)

Insulation

(By Others)

UNIT LOCATION

dANGeR

Appliances must not be installed where they may be
exposed to potentially explosive or flammable atmosphere.

CAUtIoN

Appliances are designed for outdoor installation only.
DO NOT LOCATE APPLIANCES INDOORS.

IMPoRtANt

To prevent premature heat exchanger failure, do not locate
ANY gas-fired appliances in areas where corrosive vapors (i.e.
chlorinated, halogenated or acid) are present in the atmosphere.

Location Recommendations

1. When locating the packaged rooftop unit, Model MPR,
consider general space and cooling/heating requirements and
availability of gas and electrical supply.

2. Be sure the structural support at the unit location site is
adequate to support the weight of the unit and any other
required support structure. For proper operation the unit
must be installed in a level horizontal position.

3. All mechanical equipment generates some sound and
vibration that may require attenuation. Locating the
equipment away from the critical area is desirable within
ducting limitations. Frequently, units can be located above
utility areas, corridors, restrooms, and other non-critical
areas. Generally, a unit should be located within 15 feet of
a primary support beam. Smaller deflections mean lesser
vibration and noise transmission. For critical applications,
please consult with an acoustical attenuation expert.

4. Do not install units in locations where the flue products
(if equipped with a gas fired heating option) can be drawn
into the adjacent building openings such as windows, fresh
air intakes, etc.

5. Be sure that the minimum clearances to combustible
materials and recommended service clearances are
maintained. For units with the gas heating option, be sure
clearances are maintained to the combustion air inlet
louvers and power exhauster discharge cover. Units are
designed for installation on non-combustible surfaces with
the minimum clearances shown in Figure 5.1.

6. On units that have fresh air openings, a method must be
provided to prevent water and debris from entering the unit
such as a rainhood, which is available as an accessory
from Modine. Where possible, install the unit so that the
inlet is not facing into the prevailing wind to prevent water
entrainment.

7. The exhaust fan is not designed for high temperature
or smoke control exhaust applications. Exhaust air
temperature must not exceed 104°F. Operating the
exhaust fan above 104°F will result in failure of the
exhaust fan.

Roof Curb Installation

An optional roof curb is available to simplify site preparation
and raise the unit above roof water and snow level for
drainage. It can be installed in advance of the unit. The curb
is shipped knocked down with separate instructions (Literature
#MCP15-590) for its assembly, flashing, and sealing with the
roof. The following are some general guidelines for roof curb
installed units:

1. The roof structure must be adequately designed to support
the live weight load of the unit and any other required
support structure. The roof curb should be supported at
points no greater than five feet apart. Additional truss
reinforcement should be provided, if necessary.

2. Roof curbs supplied by Modine are fabricated from 10
gauge galvanized steel and supplied knocked down for
assembly on the job site. The curb consists of two side
pieces, two end pieces, gasketing, four joiner angles, four
2x4 inch wood nailing strips, nuts, bolts, and washers.

3. Outside dimensions must be held when installing curb.
Top surface must be level and straight to ensure weather­tightness. If roof is pitched it will be necessary to construct
a sub-base on which to install the curb. All corners must
be square.

4. All dimensions are +1/8 inch.

5. When a roof curb is used in conjunction with factory
supplied discharge and/or return air connectors, the
ductwork can be fastened to the connectors prior to the
unit installation. The connectors will accept 90° flanged
ductwork (see Figure 7.1).

6. Final electric and gas connections must be made after unit
is installed to allow for tolerance in setting of unit on curb.
For electrical power supply allow approximately eight feet
of wire, plus provisions for weathertight flexible conduit for
connection to unit, as required by local codes.

7. Maintain a 12-inch minimum height from top of roof deck
to top of curb.

8. Caulk butt joints after curb is assembled and installed on
roof structural members and roof flashing is added.

9. For improved sound attentuation, line the roof deck within
the curb area with 2" acoustic fiberglass.

Figure 4.1 - Typical Curb Details

4 MCP15-500.7

CLEARANCES / ROOF CURB INSTALLATION

Figure 5.1 - Combustible Material & Service Clearances

B- AND C-CABINET UNITSWITHOUT ENERGY RECOVERY D-CABINET UNITSWITHOUT ENERGY RECOVERY

FIELD INSTALLED

SEE NOTE 2

36.0

SEE NOTE 2

36.0

ACCESSORY

RAINHOOD

48.0

SEE NOTE 3

36.0

SEE NOTE 4

FOR UNITS WITH GAS HEAT,

MAINTAIN 48" MINIMUM

FROM VENT TERMINATIONS

48.0

SEE NOTE 1

B- AND C-CABINET UNITSWITH ENERGY RECOVERY

FIELD INSTALLED

36.00

36.0

SEE NOTE 4

FOR UNITS WITH GAS HEAT,

MAINTAIN 48" MINIMUM

FROM VENT TERMINATIONS

48.0

SEE NOTE 1

ACCESSORY

RAINHOOD

48.0

SEE NOTE 3

SEE NOTE 4

48.00

SEE NOTE 3

48.00

SEE NOTE 1

FOR UNITS WITH GAS HEAT,

MAINTAIN 48" MINIMUM

FROM VENT TERMINATIONS

j The minimum recommended clearance for service is 48". For service

clearances less than shown, applicable local code requirements must be
followed. If the ability for future condenser coil replacement is desired, the
minimum clearance must be:

• 102" for B-Cabinet sized units

• 112" for C-Cabinet sized units

• 100” for D-Cabinet sized units

See Note k for alternate coil replacement direction.

k The minimum recommended clearance for service is 36". For service

clearances less than shown, applicable local code requirements must be
followed. If the ability for future condenser coil replacement is desired, the
minimum clearance must be (from the end panel of the condenser, not the
end of the inlet hood):

• 102” for B-Cabinet sized units

• 112” for C-Cabinet sized units

• 100” for D-Cabinet sized units

See Note j for alternate coil replacement direction.

l The minimum recommended clearance for service is 48". For service

clearances less than shown, applicable local code requirements must be
followed. If the ability for future evaporator coil, hot gas reheat coil, and/or
energy wheel replacement is desired, the minimum clearance must be:

• 55" for B-Cabinet sized units

• 64" for C-Cabinet sized units

• 100” for D-Cabint sized units

m Additional Required Clearances:

-Clearance above unit must be unobstructed.

-Clearance to combustibles below the unit is 6" minimum.

48.00

SEE NOTE 3

5MCP15-500.7

GENERAL RIGGING INSTRUCTIONS / UNIT INSTALLATION

SPREADER BAR

AND LIFTING

CHAINS/STRAPS

BY INSTALLER

ADJUST CHAIN/STRAP

LENGTH SO UNIT IS

LEVEL WHEN LIFTED

RAINHOOD

ACCESSORY

(FIELD INSTALL)

(4) 1.50" LIFTING EYE BOLTS

(EACH CORNER OF UNIT)

SPREADER BAR

AND LIFTING

CHAINS/STRAPS

BY INSTALLER

ENSURE THE LIFTING

CHAINS/STRAPS CLEAR

THE CASING ON EACH SIDE

(6) 1.0" LIFTING LUGS

MIN. 65

v

SPREADER BAR
AND LIFTING
CHAINS/STRAPS
BY INSTALLER

ADJUST CHAIN/STRAP

LENGTH SO UNIT IS

LEVEL WHEN LIFTED

RAINHOOD
ACCESSORY
(FIELD INSTALL)

ENSURE THE LIFTING
CHAINS/STRAPS CLEAR
THE CASING ON EACH SIDE

(4) 1.0" LIFTING LUGS

LIFTING LUG KIT IS SHIPPED LOOSE IN SUPPLY FAN SECTION.
INSTALL (4) LIFTING LUGS PER MCP15-505 USING (4) GRADE 5 BOLTS PER LUG, TORQUED TO 75 ft-lb.

B-CABINET UNIT - NO ENERGY RECOVERY
C-CABINET UNIT - ALL

D-CABINET UNIT - ALL

B-CABINET UNIT - WITH ENERGY RECOVERY

General Rigging Instructions

WARNING

Failure to follow proper lifting instructions could result in
property damage, serious injury, or death. Lifting should
only be done by a qualified rigging company. Use ALL lifting
points. Test lift to ensure proper balance and rigging. Never
lift in high winds.

Lifting Lug Installation

Before attaching lifting equipment, verify location of lifting lugs
or eyes. B- and C-Cabinet sized units have the lifting lugs or
eyes factory installed as follows:

• B-Cabinet sized units without Energy Recovery include
(4) eye bolts at each corner on the top of the unit.

• B-Cabinet sized units with Energy Recovery include (6)
lifting lugs on the base, one at each corner and one on
each length-wise side of the unit between the corners.

• C-Cabinet sized units include (4) eye bolts at each corner
on the top of the unit. For units that include the shipped
separate Energy Recovery Module (model ERM) option,
refer to the latest revision of the Installation and Service
Manual, #MCP15-520, that shipped with the ERM for
separate rigging instructions.

• D-Cabinet sized units must have the lifting lugs installed in
the unit base assembly prior to rigging as follows:

1. Locate the lifting lug kit box, kit # 66802, located in

the supply fan compartment.

2. Install the kit per the “Installation Instructions, Lifting

Lugs D-Cabinet”, #MCP15-505, included with the kit.

3. After installing the kit, verify that all (4) lugs are

installed following the instructions in Step 2. Verify
that each lug is secured using (4) Grade 5 bolts
provided with the kit. Each bolt must be torqued to
75 ft-lb.

Unit Rigging and Lifting

Rigging and lifting of the units should only be done by a
qualified rigging company. With the lifting lugs or eyes
identified and installed, the units can be lifted by crane or
helicopter.

1. Follow site preparation instructions for the roof curb or
equipment stand before installation.

2. Check the Serial Plate(s) of unit with plans to be sure unit
is properly located. Although units may look outwardly
similar, their function, capacities, options, and accessories
will often vary.

3. Check unit dimensions of both the unit base and the curb
or stand on which the unit will be installed.

4. If the unit will be installed on a roof curb:

a. Thoroughly clean and dry the top of the curb surface.

b. Lay a bead of weather resistant caulking on top

perimeter of roof curb as illustrated in Figure 7.1. Note:
If roof curb is supplied by Modine, full perimeter gasket
material is supplied and caulking is not necessary.

5. When lifting the equipment, connect sturdy steel cables,
chains, or straps with eye loops as illustrated in Figure 6.1.
For stability in lifting and lowering and to prevent damage
to the unit, include a spreader bar as illustrated in Figure

6.1. Avoid twisting or uneven lifting of the unit. The cable
length from the lifting point on the unit to the spreader bar
should always be longer than the distance between the
outer lifting points.

6. Test lift the unit to check for proper rigging balance before
hoisting to the desired installation location.

7. Once lifted to the installation location, orient the hoisted
unit to match the ductwork locations and set evenly on the
curb or stand.

8. Following the instructions in this manual, make final unit
connections to the electric power supply and remote
control circuits. Connect the gas lines to the unit heating
compartment. Seal all utility line clearance holes on the unit
after connections are completed so they are watertight.

Figure 6.1 - Typical Rigging for Model MPR

6 MCP15-500.7

DUCT INSTALLATION AND UTILITY CONNECTIONS

RETURN AIR
CONNECTOR

DISCHARGE AIR
CONNECTOR

90° FLANGED
DUCTWORK

(By Installer)

UNIT BASE
(Shown without
unit for clarity)

ROOF
CURB

BEFORE UNIT
INSTALLATION
CAULK ALL MATING
SURFACES ➀
(Caulk by installer)

➀ If roof curb is supplied
by Modine, full perimeter
gasket material is supplied
and caulking is not necessary.

Duct Installation

1. The unit is designed to accept 90° flanged ductwork on both
the supply and return air openings. Refer to the roof curb or
the unit base dimensional drawings to determine the location
of the openings.

2. Acoustic duct liners are recommended on all internal supply
and return air ducts.

3. When ductwork is installed prior to unit arrival, flexible
connections should be included to make connections easier
and to simplify possible future service.

4. When a roof curb is used in conjunction with factory supplied
discharge and/or return air connectors, the ductwork can be
fastened to the connectors prior to the unit installation. The
connectors will accept 90° flanged ductwork (see Figure 7.1).

Figure 7.1 - Discharge and/or Return Air Connectors

5. To assure proper air flow from the unit, follow these duct
design recommendations:

a. Be sure ducts are properly sized and installed.
b. As a general rule, all discharge ducts should have a

A = Cross Sectional Area of Rectangular Duct
P = Perimeter of Rectangular Duct
D = Diameter of Round Cut

c. Wherever turns in the duct work are made, include

d. Supply air ducts in a “T” configuration should be

avoided to prevent air temperature stratification. If this
configuration must be used, provide appropriate mixing
devices and/or the necessary straight duct length before
the “T” to provide uniformly mixed air temperature
delivery to both supply air duct trunks.

Utility Connections

Utility and control connections can be made to the unit from
the bottom or through the fixed side panels. Holes can be field
drilled in fixed side panels to accommodate utility connections
as shown on the unit dimensional drawings and the utility
entrance location area label located on the unit. All gas and
electrical connections to the unit must be weatherized so they
are watertight.

straight run of at least three (3) hydraulic duct diameters
before making turns in the ductwork.

Hydraulic Duct Diameter for Rectangular Ducts = 4A/P
Hydraulic Duct Diameter for Circular Ducts = D
where:

turning vanes.

7MCP15-500.7

CONDENSATE DRAIN INSTALLATION

Evap Condensate Drain Trap Installation

IMPoRtANt

A properly designed drain with trap must be installed
immediately after the unit evaporator coil condensate drain
pan connection. Failure to do so will result in condensate
that cannot properly drain from the unit, eventually causing
the drain pan to fill. To prevent damage to the building or
unit, a drain pan float switch is included as standard and will
disable the unit if the maximum condensate level is reached.

All units require a drain system with a condensate trap to be

connected to the condensate drain pan connection which is
accessible from the exterior of the unit casing. Failure to install
a condensate drain trap may result in condensate overflowing
from the drain pan, causing damage to the unit and building.
See Figure 30.1 or 31.1 for location. The drain system is to be
installed as follows:

1. The condensate drain pan includes a 1-1/4" female NPT
stainless steel connection accessible from the exterior of the
unit casing. Do not reduce the drain diameter. A drain pan
connection kit is shipped loose for field installation to allow
connection exterior to the casing. Refer to Figure 8.1 for
assembly details.

Figure 8.1 - Condensate Drain Pan Connection Kit

Threaded Connection on
Evap Coil Drain Pan

Threaded Nipple

Note: All kit components shown
are factory supplied for field installation.

Rubber Washer

Corrosion Resistant
Steel Washer

Corrosion Resistant
Steel Locknut

Figure 8.2 - Condensate Drain Trap Installation

Note: All piping components
shown are supplied by others.

 •Thetrapdepthmustbe½xthetrapheight.Forexample,if

the trap height is the minimum 6”, the trap depth must be 3”
(see Figure 8.2).

 •Formaintenance,itisrecommendedtohaveacapped

cleanout at the top of the trap as shown in Figure 8.2.

5. After the exit from the trap, the drain must be pitched
down from the unit connection at least 1” for every 10 feet
of horizontal run to promote proper drainage. If the local
installation code allows, the drain can be run to a waste
water system.

6. If the trap may experience below freezing temperatures
during non-cooling periods, heating wraps must be used to
avoid water from freezing in and damaging the trap and drain
system.

7. The trap must be primed before the unit is put into operation
and properly maintained on a regular schedule. Refer to the
Start-Up Procedure section and the Maintenance section for
additional guidance.

TRAP HEIGHT

(6" MINIMUM)

CAPPED
CLEANOUT

1/2 x TRAP

HEIGHT

2. The drain line should include provisions for disconnecting the
line at or near the unit for maintenance/servicing of the unit.
The drain line must not interfere with access panels, which
are removable for maintenance/service.

3. The drain line must include a trap immediately after the
unit, as shown in Figure 8.2. Failure to do so will result
in condensate that cannot properly drain from the unit,
eventually causing the drain pan to fill and overflow. If the
drain pan overflows, significant damage can occur to the unit
and/or building on which the unit is installed. A drain pan float
switch is included as standard and will disable the unit if the
maximum condensate level is reached.

4. The design of the trap is critical to ensure proper drainage.
If the trap is not constructed properly with the dimensions
as outlined in the following instructions, air could be drawn
through the drain pipe and into the system or could back up
into the drain pan.

 •Thedrainislocatedonthesuctionsideofthemain

supply air fan, resulting in a negative pressure relative to
outside the unit cabinet. The trap height must be at least
6” to account for maximum negative pressure, including
allowance for dirty filters. Note that the trap height is the
difference in height from the drain connection of the unit to
the leaving side of the trap. Refer to Figure 8.2.

8 MCP15-500.7

ELECTRICAL CONNECTIONS

Electrical Connections

WARNING

1. Disconnect power supply before making wiring
connections or working on this equipment. Follow all
applicable safety procedures to prevent accidental
power up. Failure to do so can result in injury or death
from electrical shock or moving parts and may cause
equipment damage.

2. For units equipped for dual power supply sources, both
sources of power must be disconnected to prevent
electrical shock and equipment damage.

3. All appliances must be wired strictly in accordance with
the wiring diagram furnished with the appliance. Any
wiring different from the wiring diagram could result in a
hazard to persons and property.

4. Any original factory wiring that requires replacement
must be replaced with wiring material having a
temperature rating of at least 105°C.

5. Ensure that the supply voltage to the appliance, as
indicated on the serial plate, is not 5% greater than
rated voltage.

roltage.

CAUtIoN

Ensure that the supply voltage to the appliance, as indicated
on the serial plate, is not 5% less than the rated voltage.

1. Installation of wiring must conform with local building
codes, or in the absence of local codes, with the National
Electric Code ANSI/NFPA 70 - Latest Edition. Unit must be
electrically grounded in conformance to this code. In
Canada, wiring must comply with CSA C22.1, Part 1,
Electrical Code.

2. Two copies of the job specific wiring diagram are provided
with each unit, one permanently affixed to the inside of the
door of the controls compartment and the other as a loose
copy with the literature packet that ships with the unit.
Refer to this diagram for all wiring connections.

3. Control wiring consists of both 24V analog control wiring
and low current digital control signal wiring. To avoid signal
interference, the two types should be run in separate
conduits. If run in the same conduit, the digital signal wiring
should be shielded at one end of the wiring run. Wiring
should be twisted, stranded, and shielded communication
wire.

4. The wire gauge must be sized according to the National
Electric Code or CSA code based on amp draw and length
of run. Refer to Table 9.1 for maximum wire lengths and
the number of wires that can be wired to each low voltage
terminal block based on the wire gauge being used.

Table 9.1 - 24V and Digital Control Wire Lengths

Minimum

Recommended

Wire Gauge

22 n/a 120

20 n/a 200

18 75 300

16 125 500

14 175 n/a

24V Control Wiring Digital Control Wiring

Maximum Distance from

Control Device to Unit

5. For field wiring to the factory terminal strip, the terminal
strip connections are designed to clamp down on the wires.
To properly connect the wires to the terminal strip:

• Push a small flat-head screwdriver into the square hole on
the terminal. Press firmly until the screwdriver hits the
back stop and opens the terminal (see Figure 9.1).

• Remove approximately 3/8” of insulation from the end of
the wire and push the stripped wire into the oval hole in
the terminal.

• Remove the screwdriver. Pull on the wire to make sure
that it is securely clamped in the terminal.

• Make sure that the terminal clamp is in contact with bare
wire (insulation removed).

Figure 9.1 - Terminal Strip Wiring

Oval Holes

for Wiring

(two rows each)

Square Holes

for Wire Release

(two rows each)

Terminal

Numbers

Test Probe

Points

6. Depending on the configuration of the unit controls, there
may be sensors that are field installed. Review the unit
ordered to verify that the sensors supplied match the
configuration of the unit. The following are sensors that
may be included for field installation:

• Supply Air Temperature Sensor

This sensor is required on all units and should be
mounted in the supply air ductwork downstream of the
unit. The sensor should be located at least 5 feet, but not
more than 20 feet downstream from the unit discharge.

• Space Temperature/Humidity Sensor

This sensor is required on all units that have space
temperature/humidity reset control. The sensor is to be
wall-mounted in the space at a height of approximately
5 feet from the floor.

• Building Pressure Sensor
This sensor is required on all units that have space
pressure control, either through modulating dampers or
variable frequency drive control on the supply air blower.
The sensor is to be mounted inside a control panel in the
space and includes two pressure taps. One pressure tap
is for outside atmospheric pressure reference, the other is
for sampling the space pressure.

• Duct Pressure Sensor

This sensor is required on all units that have duct
pressure control through variable frequency drive control
on the supply air blower. The sensor is to be mounted
with the sensing probe inserted into the supply duct. The
atmospheric pressure sampling tap is left open.

9MCP15-500.7

ELECTRICAL CONNECTIONS / GAS CONNECTIONS

• Space CO2 Sensor

This sensor is required on all units that have demand
based ventilation control. The sensor is to be mounted in
the space at a height of approximately 5 feet from the
floor.

• Duct Mounted Smoke Detector

When ordered as a field installed accessory, the detector

should be mounted in the supply air or return air ductwork.

For further instructions on the above sensor(s), refer to
the installation instructions that shipped with the
sensor(s).

7. If the unit is a C-Cabinet sized unit with a Modine supplied
Energy Recovery Module, Model ERM, the wiring
connection between the MPR unit and the ERM unit must
be made by extending the loose end of the wire drop
located in the MPR unit outside air damper section, through
the transition duct between units, and connected to the
ERM control panel. Refer to the Installation & Service
Manual that shipped with the ERM (Literature #MCP15-

520) for additional instructions. If the unit is a B-Cabinet
sized unit with integral Energy Recovery, the unit is already
factory wired to the Energy Recovery section.

8. The power supply to the unit must be protected with a
fused or circuit breaker disconnect switch. Refer to the
Figures on pages 32 through 35 for the location of the
factory installed dead front disconnect option, if provided.
Field installed disconnect switches should be mounted
where required by the National Electric Code. Refer to the
Model Serial plate for MCA and MOP values for the unit.

9. The power supply must be within +/-5% percent of the
voltage rating and each phase must be balanced within 2
percent of each other. If not, advise the utility company.

10. External electrical service connections that must be
installed include:

a. Supply power (120, 208, 240, 480, or 600 volts).
b. Thermostats, building pressure sensors, or any other

accessory control devices that may be supplied (24
volts).

11. All outdoor electrical connections must be weatherized to
prevent moisture from entering the electrical compartment.

12. Electrical connections are made in the controls cabinet and
can be run through the bottom or side of the unit. Refer to
the unit and base dimensional drawings for locations of
wiring entrance. Refer to the wiring diagram for the terminal
location of all low voltage wiring.

REVIEW BEFORE PROCEEDING

THIS SECTION APPLIES TO UNITS WITH

(MODEL DIGIT 17=2 OR 3).

IF THE UNIT DOES NOT HAVE GAS HEAT,

Gas Connections

WARNING

1. All field gas piping must be pressure/leak tested prior
to operation. Never use an open flame. Use a soap
solution or equivalent for testing.

2. Gas pressure to appliance controls must never
exceed 14" W.C. (1/2 psi).

3. To reduce the opportunity for condensation, the
minimum sea level gas input to the appliance, as
indicated on the serial plate, must not be less than
5% below the rated input, or 5% below the minimum
rated input of dual rated units.

CAUtIoN

Purging of air from gas supply line should be performed as
described in ANSI Z223.1 - latest edition “National Fuel Gas
Code”, or in Canada in CAN/CGA-B149 codes.

IMPoRtANt

To prevent premature heat exchanger failure, the input to the
appliance, as indicated on the serial plate, must not exceed
the rated input by more than 5%.

1. Installation of piping must conform with local building codes,
or in the absence of local codes, with the National Fuel Gas
Code, ANSI Z223.1 (NFPA 54) - Latest Edition. In Canada,
installation must be in accordance with CAN/CGA-B149.1 for
natural gas units and CAN/CGA-B149.2 for propane units.

2. Piping to units should conform with local and national
requirements for type and volume of gas handled, and
pressure drop allowed in the line. Refer to Table 11.1 to
determine the cubic feet per hour (cfh) for the size of unit
to be installed. Using this cfh value and the length of pipe
necessary, determine the pipe diameter from Table 11.2.
Where several units are served by the same main, the total
capacity, cfh and length of main must be considered. While
the gas connection(s) on the unit may be smaller than 1", do
not use pipe sizes smaller than 1" leading up to the unit. At
the unit, reduce the pipe size down to the appropriate size
(refer to Table 11.1 for connection sizes). Table 11.2 allows
for a 0.3" W.C. pressure drop in the supply pressure from the
building main to the unit. The inlet pressure to the unit must
be 6-7" W.C. for natural gas and should not drop below 6.0"
W.C. when the unit is operating. When sizing the inlet gas
pipe diameter, make sure that the unit supply pressure can
be met after the 0.3" W.C. has been subtracted. If the 0.3"
W.C. pressure drop is too high, refer to the Gas Engineer’s
Handbook for other gas pipe capacities.

OPTIONAL GAS HEAT

SKIP TO PAGE 15.

roltage.

10 MCP15-500.7

GAS

GAS CONNECTIONS

Furnace Size

(Btu/hr)

Gas Consumption

(CFH)

Gas

Connection

Table 11.1 - Natural Gas Heating Gas Consumption

Digit 6 Digit 18

F 150,000 143 1/2"

G 200,000 190 3/4"

H 250,000 238 3/4"

B

J 300,000 286 3/4"

K 400,000 381 3/4"

R 175,000 167 1/2"

S 225,000 214 3/4"

T 310,000 295 3/4"

J 300,000 286 3/4"

K 400,000 381 1"

C 

L 500,000 476 1"

L 600,000 571 1"

U 350,000 333 1"

V 450,000 429 1"

K 400,000 381 1.5" x 2

L 500,000 476 1.5" x 2

M 600,000 571 1.5" x 2

Q 800,000 762 1.5" x 2

D 

1 900,000 857 1.5" x 2

2 1,000,000 952 1.5" x 2

3 1,200,000 1143 1.5" x 2

4 1,400,000 1333 1.5" x 2

5 1,600,000 1524 1.5" x 2

j Natural gas consumption based on a heating value of 1050 Btu/cu. ft.
k C-Cabinet units consist of two furnaces that together total the value shown in

Table 11.1.

l D-Cabinet units consist of two furnaces that together total the value shown

in Table 11.1 for sizes up to 800,000 Btu/hr. For sizes over 800,000 Btu/hr,
the unit consists of four furnaces that together total the value shown in Table

11.1.



3. The gas piping to the unit can enter the unit from the side
of the unit (refer to the unit dimensions) or from below (refer
to the base dimensions). A drill locator sticker and dimple is
located on the side of the unit to indicate the safe area for
drilling the hole for side gas pipe entry on B- and C-Cabinet
sized units. D-Cabinet sized units include a holes with
grommets for side pipe entry. Install a ground joint union
with brass seat and a manual shut-off valve external of the
unit casing, and adjacent to the unit for emergency shut-off
and easy servicing of controls, including a 1/8" NPT plugged
tapping accessible for test gauge connection (see Figure

11.1). Verify the manual shut-off valve is gas tight on an
annual basis.

NOTE: For bottom piped units, some local codes may require

a manual shutoff valve external to the unit casing. In this case,
the gas piping must exit the unit through the side, followed by
the manual shut-off valve, piped back into the unit side, and
lead to an additional union and manual shut-off valve.

4. Provide a sediment trap before each unit in the line where
low spots cannot be avoided (see Figure 11.1).

5. When Pressure/Leak testing pressures above 14" W.C.
(1/2 psi), close the field installed shut-off valve, disconnect
the appliance and its combination gas control from the gas
supply line, and plug the supply line before testing. When
testing pressures 14" W.C. (1/2 psi) or below, close the
manual shut-off valve on the appliance before testing.

Figure 11.1 - Recommended Sediment Trap/Manual

Shut-off Valve Installation

GAS

SUPPLY LINE

SUPPLY LINE

MANUAL GAS 

SHUT-OFF VALVE

GROUND JOINT

UNION WITH
BRASS SEAT

Table 11.2 - Gas Pipe Capacities (Cu. Ft. per Hour) m

Pipe

Length

(feet)

1" 1-1/4" 1-1/2" 2"

10 520 1050 1600 3050
20 350 730 1100 2100
30 285 590 890 1650

40 245 500 760 1450
50 215 440 670 1270
60 195 400 610 1150
70 180 370 560 1050
80 170 350 530 990

90 160 320 490 930
100 150 305 460 870
125 130 275 410 780
150 120 250 380 710

m Gas pipe capacities based on gas pressure up to 14" W.C. through Schedule

40 pipe with a pressure drop of 0.3" W.C. for Natural gas with a specific
gravity of 0.60.

Gas Pipe Diameter

TO GAS

CONTROLS

MIN.

3"

PLUGGED

1/8" NPT TEST

GAUGE CONNECTION

Side Gas Connection

SEDIMENT

TRAP

CONTROLS

PLUGGED 1/8"

NPT TEST GAUGE

CONNECTION

Through hole

in bottom of unit.

(caulk hole to prevent

GROUND

JOINT
UNION

W/ BRASS

SEAT

water leakage.)

MANUAL GAS

SEDIMENT

TRAP

SHUT-OFF VALVE

GAS

SUPPLY LINE

Bottom Gas Connection

j Valve is in the “OFF” position when handle is perpendicular to pipe.

MIN.

3"

j

TO

11MCP15-500.7

GAS HEATING OPTION VENT TERMINALS AND COMBUSTION AIR HOODS

Vent

Terminals

Combustion

Air Hoods

6

Type

Field Installe d Qty

(Btu/hr)

18

Vent Terminals and Combustion Air Hoods

1. Do not operate the units without the factory supplied (shipped
loose) power exhauster vent system/vent termination(s) or
combustion air hoods if applicable. Refer to Table 12.1 to
determine how many terminals and hoods are required based
on the model MPR nomenclature.

2. Do not modify or obstruct the combustion air inlet louvers or
the power exhauster discharge cover terminations.

3. Do not add any vents other than those supplied by the
manufacturer. For units that require vent extension kits, refer
to Literature #MCP15-574, “Installation Instructions,
Extended Vent Kit, Model MPR Gas Heat”.

Table 12.1 - Power Exhauster Vent Terminal and

Combustion Air Hood Quantity

Digit

B

C

D

Furnace Size

Digit

F 150,000

G 200,000

H 250,000

J 300,000

K 400,000

R 175,000

S 225,000

T 310,000

J 300,000

K 400,000

L 500,000

L 600,000

U 350,000

V 450,000

K 400,000

L 500,000

M 600,000

Q 800,000

1 900,000

2 1,000,000

3 1,200,000

4 1,400,000

5 1,600,000

Furnace

Non-

Condensing

Condensing

Non-

Condensing

Condensing

Non-

Condensing

Non-

Condensing

1

1 n/a

2

2

2 2

4 2

n/a

n/a

n/a

Non-Condensing Furnaces (B, C, or D-Cabinet)

For Non-Condensing furnace types, as determined from Table

12.1, refer to Figure 12.1 for vent termination installation details,
otherwise skip to the section titled Condensing Furnaces. For
units that require vent extension kits, refer to Literature
#MCP15-574, “Installation Instructions, Extended Vent Kit,
Model MPR Gas Heat”.

Figure 12.1 - Power Exhauster Vent Terminal for

Non-Condensing Gas Furnace Option

Note: Caulk mating
surfaces before

2

Gas Furnace

Vent Outlet

k C-Cabinet sized unit shown with two vent terminals. B-Cabinet sized units

have only one and D-Cabinet with have either one on each side of the
cabinet (two total) or two on each side of the cabinet (four total).

attaching to the unit

(6) Screws for
Fastening Gas
Furnace Vent
Outlet Cover
(supplied with kit)

For D-Cabinet units, the furnace doors must have the
combustion air hoods field installed as shown in Figure 12.2,

using the screws included with the kit. Once complete, proceed
to the “Start-Up” section.

Figure 12.2 - Combustion Air Hood Installation

(D-Cabinet only)

For specific instructions on each configuration in Table 12.1,
refer to the appropriate section from the following sections
titled:

• Non-Condensing Furnaces (B, C, or D-Cabinet), or

• Condensing Furnace (B-Cabinet), or

• Condensing Furnace (C-Cabinet)

12 MCP15-500.7

Note: Caulk mating surfaces
before attaching to the unit.

Also shown are the vent terminals for reference.

(refer to

Instructions

Step 1)

(refer to Instructions Step 3)(refer to Instructions Step 2)

(refer to Instructions Step 1) (refer to Instructions Step 2)

GAS HEATING OPTION VENT TERMINALS AND COMBUSTION AIR HOODS

Condensing Furnaces (B-Cabinet)

For B-Cabinet units with Condensing furnace types, as
determined from Table 12.1 on page 12, refer to Figures 13.1
and 13.2 for vent termination installation details. The
installation steps are as follows:

Step 1: Insert short vent pipe length into the vent pipe

reducer. Insert that assembly into the rubber coupling
on the power exhauster outlet. Tighten the clamp on
the flexible coupling to secure the vent pipe.

Step 2: Insert the outer vent pipe with termination elbow

through the enclosure wall grommet and into the vent
pipe section installed in Step 1.

Once complete, proceed to the “Condensate Drain and Trap
Installation” section.

Condensing Furnaces (C-Cabinet)

Figure 13.1 - Power Exhauster Vent Terminal for

Condensing Gas Furnace Option

For C-Cabinet units with Condensing furnace types, as
determined from Table 12.1 on page 12, refer to Figures 13.3
and 13.4 for vent termination installation details. The
installation steps are as follows:

Step 1: Insert small diameter outside vent pipe termination

through enclosure wall grommet and into the flexible
rubber coupling on the right side power exhaust
outlet. Tighten the clamp on the flexible coupling to
secure the vent pipe.

Step 2: Insert large diameter inner vent pipe assembly into

the flexible rubber coupling on the left side power
exhaust outlet. Tighten the clamp on the flexible
coupling to secure the vent pipe.

Step 3: Insert large diameter outside vent pipe termination

through enclosure wall grommet and into the
interlocking joint of the inner vent pipe assembly from
Step 2.

Step 4: Verify that the bird screens are inserted in the outlet

elbow.

Once complete, proceed to the “Condensate Drain and Trap
Installation” section.

Figure 13.3 - Power Exhauster Vent Terminal for

Condensing Gas Furnace Option

Figure 13.2 - Orientation of Installed Vent Terminal
for Condensing Gas Furnace Option (B-Cabinet)

Discharge Elbow must be

oriented to exhaust

straight down.

Figure 13.4 - Orientation of Installed Vent Terminal
for Condensing Gas Furnace Option (C-Cabinet)

Discharge Elbows must

be oriented to exhaust

straight down.

13MCP15-500.7

3/4" Threaded Elbow on Heat Exchanger Drain
Assembly (included with kit)

3/4" Male Threaded PVC Adapter
(included with kit)

3/4" PVC Pipe (by others) with Sufficient Length
to Reach the Heat Exchanger Drain Assembly
from the Inside of the Building

3/4" Unions (by others)
Recommended for Ease of Future Service

PVC "EZ-Trap" (included with kit) for
Proper Drain Trapping (a 3/4" to 1" bushing
by others may be required)

Note: The trap must be located in a heated
space or protected to avoid freezing.

Vacuum Breaker and Drain Piping
Components (by others)

To Building
Drain System

From Heat

GAS HEATING OPTION CONDENSATE DRAIN AND TRAP INSTALLATION

Condensate Drain and Trap Installation
(Condensing Furnace Type Only)

For Condensing furnace types, as determined from Table 12.1
on page 12, during heating operation, condensate is produced
in the furnace sections. The installation requires condensate
drain systems from each furnace section, as shown in Figures

14.1 and 14.2 and described below. Condensate trap kits are

provided with the unit.

1. For proper heating system performance, the condensate

drain system must include a trap for each furnace.
B-Cabinet units have one furnace while C-Cabinet units
have two furnaces.

2. All joints must be watertight to prevent leakage of

condensate. The drains must be extended down through
the base of the unit and into the heated space below.

3. Each heat exchanger drain assembly includes a threaded

elbow that is oriented down. Once the male threaded PVC
adapters, included with the kit, are glued to the PVC drain
pipe (by others) that extends into the space, they are to be
routed up through the holes in the unit base pan and
screwed into the elbow connections. The threads must be
sealed to prevent leaks.

4. Unions are recommended to permit maintenance of the

drains and to facilitate service of the heater. A union is
shown on both sides of each trap.

5. A vacuum breaker is required after each trap. The vacuum

breaker should be constructed so that dirt and debris do
not enter and clog the drain system.

6. Local code permitting, the condensate drain systems may

be joined after the traps and connected to a sanitary drain
within the building. Because the condensate produced is
acidic, some municipalities may require that the
condensate be neutralized before being discharged into the
sanitary sewer. A condensate neutralizer tube kit is
available from Modine to reduce the pH of the condensate.
A single tube can be used for drains that are joined after
the traps providing the tube is installed after the junction.
Refer to the instructions that come with the kit.

7. For proper operation, the traps must be primed with water.

The traps must be installed with the higher side connected
to the heater and the lower side connected to the drain.

8. If there is an opportunity that the temperature in the space

will fall below freezing during non-operating periods, the
condensate drain systems and secondary heat exchanger
must be completely drained to prevent freeze damage.
Alternately, heat tape can be applied to the drain pipe
system in accordance with the heat tape manufacturers
instructions.

Figure 14.1 - Furnace Condensate Drain/Trap

System j

j C-Cabinet sized unit shown with two condensate drain systems. B-Cabinet

sized units require only one drain system.

Figure 14.2 - Drain System Trap/Vacuum Breaker

Exchanger Drain
Assembly on Unit

Note: Drain pipe from unit

Vacuum Breaker

To Building
Drain System

Note: Refer to figure above for determination of parts supplied by others.

must enter the high side of
the drain trap.

14 MCP15-500.7

HOT WATER PIPING CONNECTIONS

REVIEW BEFORE PROCEEDING

THIS SECTION APPLIES TO UNITS WITH

OPTIONAL HOT WATER HEAT

(MODEL DIGIT 17=4).

IF THE UNIT DOES NOT HAVE HOT WATER

HEAT, SKIP TO PAGE 16.

CAUtIoN

1. Units not approved for use in potable water systems.

2. Do not operate the unit with steam. The coil is not designed
for steam condensate removal which can damage the unit.

3. Hot water supplied to the hot water heating option must
not exceed 180°F temperature or 75 PSIG pressure.

1. Models with a factory installed hot water heating coil (for use
with water or propylene glycol fluids) are supplied with 1-1/2"
sweat connections (1.625").

Figure 15.1 - Hot Water Coil Connections

 •On3-wayvalvecontrolconfigurations,includeabalancing

valve between the supply line and control valve to balance
the system.

 •Includeahosebibdrainvalveonthebottomofthesupply

manifold to allow for periodic flushing of the system to
remove sediments from the coil.

 •Includeapipelinestraineronthesupplylinetoprevent

sediment from reaching the coil.

 •Includeanairventatthetopofthereturnmanifoldtobleed

off accumulated air in the system. Air in the system will
generate noise and may cause water hammer that can
damage the joints of the piping and coil.

 •Includeeithera2-wayor3-waymodulatingcontrolvalve

designed for a 0-10VDC control signal. The valves will be
automatically modulated by the unit’s Carel controller to
maintain the supply air temperature setpoint. Note that the
control valve must be a normally open, spring return type
valve. This is to allow hot water to flow through the coil for
freeze protection when the unit is shut down. Refer to the
Freeze Stat Option section for additional detail.

 •Hotwaterpipesshouldbeinsulatedtoreduceheatlossand

to prevent overheating of the end compartment.

9. Leak test the coil and connections as outlined in the
Start-Up section.

Figure 15.2 - Typical 2-Way Piping Installation
(piping and components by others)

Supply Connection Return Connection

2. The entering water temperature (EWT) supplied to the
heating coil must not exceed 180°F.

3. The fluid flow rate must not exceed 50 gallons/minute (GPM)
and fluid pressure must not exceed 75 psi.

4. It is recommended to use an inhibited glycol solution that is
designed for HVAC applications for corrosion protection and
freeeze protection for the lowest possible outside air
temperatures for the installed location. Failure to protect
against freezing can result in damage to the coil and
property.

5. Provide adequate pipe hangers, supports, or anchors to
secure the piping system independently of the coil to prevent
excess vibration and stress that can damage the piping and
joints.

6. All field brazing and welding should be performed using high
quality materials and an inert gas purge (such as nitrogen) to
reduce oxidation of the internal surface of the coil.

7. System piping should be flexible enough to allow for thermal
expansion and contraction of the coil and piping components.

8. Refer to Figures 15.2 and 15.3 for typical piping system
design and the following recommended items:

 •Installshut-offvalvesinlinestoandfromtheunittoallow

for maintenance or replacement of the coil without shutting
down and draining the entire system.

 •Installunionsforeaseofpipingcomponent/coilremoval.
 •Includeacircuitsetterinthereturnlinetoregulateflow.

HOSE BIB DRAIN

SHUT-OFF

VALV E

SHUT-OFF

VALV E

SUPPLY

RETURN

HOT WATER

COIL

AIR VENT

UNION

UNION

2-WAY CONTROL

VALV E

STRAINER

UNION

CIRCUIT
SETTER

Figure 15.3 - Typical 3-Way Piping Installation

(piping and components by others)

HOSE BIB DRAIN

SHUT-OFF

VALV E

SHUT-OFF

VALV E

SUPPLY

RETURN

HOT WATER

COIL

AIR VENT

UNION

UNION

BALANCING

VALV E

3-WAY CONTROL

VALV E

UNION

STRAINER

UNION

CIRCUIT
SETTER

Optional Factory Installed Freeze Stat

When equipped with the optional Coil Freeze Stat, an auto­resetting capillary type freeze stat (see Figure 50.1) is factory
installed immediately below and across the face of the hot
water coil. The stat is set to trip at 40°F (adjustable) and will
automatically reset when the coil temperature rises 5°F above
the setpoint. If the stat has tripped, the unit controls would
respond by closing the outdoor air damper, opening the return
air damper (if applicable), de-energize the supply air fan, open
the hot water coil valve 100%, and log the alarm on the
controller. The freeze stat can be removed from the unit for
servicing as discussed in the Maintenance section.

15MCP15-500.7

START-UP PROCEDURE

General

1. When the dead front disconnect switch(es) (for main
unit and/or powered convenience outlet option) is in the
“OFF” position, supply power remains energized at the
line (supply) side of the dead front disconnect switch(es).
The switch body is located inside of another junction
box to protect against contact with the live wiring.
The junction box must not be disassembled unless
the main power supply from the building to the unit is
de-energized.

2. For units equipped for dual power supply sources, both
sources of power must be disconnected to prevent
electrical shock and equipment damage.

WARNING

WARNING

CAUtIoN

When servicing the unit, some components may be hot
enough to cause pain or injury. Allow time for cooling of hot
components before servicing.

IMPoRtANt

1. To prevent premature heat exchanger failure, check to
be sure the blower has been set to deliver the proper
airflow for the application. Refer to page 17 for Blower
Adjustments.

2. Start-up and adjustment procedures must be performed
by a qualified service agency.

3. All scroll compressors requires the correct supply
power phase rotation. Phase reversal may result in
compressor failure not covered under warranty. Refer to
the Start-Up Procedure section.

4. The exhaust fan is not designed for high temperature
or smoke control exhaust applications. Exhaust air
temperature must not exceed 104°F. Operating the
exhaust fan above 104°F will result in failure of the
exhaust fan.

1. Turn off power to the unit at the disconnect switch. If
equipped with gas heating option, turn all hand gas valves
to the “OFF” position.

Note: The dead front disconnect switch, if included, is
factory installed in the controls/compressor compartment
section (refer to the figures on pages 32 through 35). The
disconnect switch is designed so that it must be turned
“OFF” before entry to the compartment can be obtained.
When in the “OFF” position, power is disconnected to all
unit wiring electrically following the switch (see
WARNING).

2. For units equipped for dual power supply sources, both
sources of power must be disconnected to prevent
electrical shock and equipment damage.

3. Open the power compartment, controls compartment, and
blower access doors.

4. Check that the supply voltage matches the unit supply
voltage listed on the Unit Serial Plate. For units equipped
for dual power supply sources, the voltage on both the
main feed and the auxiliary feed must match the unit
supply voltage listed on the Unit Serial Plate.

5. Check that fuses or circuit breakers are in place and sized
correctly.

6. Verify that all wiring is secure and properly protected. Trace
circuits to ensure that the unit has been wired according to
the wiring diagram.

7. Check that all electrical and gas connections are
weatherized.

8. For C-Cabinet sized units, if the unit is installed with a
Modine supplied Energy Recovery Module, Model ERM,
verify that the wiring connection between the MPR unit and
the ERM unit has been properly installed. If the unit is a
B-Cabinet sized unit with integral Energy Recovery, the unit
is already factory wired to the Energy Recovery section.

9. For units with gas heating, check to ensure that the
combustion air inlet louvers and the power exhauster
discharge cover (Non-Condensing as determined from
Table 12.1 on page 12) or the vent elbow terminations
(Condensing as determined from Table 12.1 on page 12)
are free from obstructions.

10. For units with condensing gas heating, check that the
condensate drain system is properly installed and the trap
has has been primed with water.

11. For units with Hot Water Heat (Digit 17=4), check the
following:

• Open air vents so that air is eliminated from within the coil
circuitry and headers. Verify that vents and drains are not
obstructed and do discharge a stream of water.

• Open all required valves to fill the coil. Once the coil is
full, close all air vents.

• Perform an initial hydrostatic leak test of all brazed,
threaded or flanged joints, valves and interconnecting
piping, and the hot water coil. Recheck the coil level and
correct if necessary.

• When the setup is found to be leak free, flush the coil
through the drain valve to eliminate grease, oil, flux and
sealing compounds present from the installation.

• Recheck the coil and all connections for water leaks.

• Check water flow rates and pressure drops and compare

to design.

• Check that the hot water supplied to the coil does not
exceed 180°F temperature or 75 PSIG pressure. Verify
that the appropriate glycol mixture is used for freeze
protection.

12. Check to see that there are no obstructions to the intake
and discharge of the unit.

13. Verify that the belts are aligned in the sheave grooves
properly and are not angled from sheave to sheave.

14. On belt driven blowers, blower bearings are permanently
lubricated unless they are pillow block bearings or if they
have grease fittings. For motors or blower bearings that are
not permanently lubricated, lubricate according to the
manufacturer’s instructions. Refer to the Maintenance
section on page 48.

15. Check to make sure that all filters are in place and that
they are installed properly according to direction of air flow.
Pleat direction must be vertical to ensure optimum
performance.

16. Perform a visual inspection of the unit to make sure no
damage has occurred during installation.

16 MCP15-500.7

START-UP PROCEDURE - CONTINUED

17. Check that the evaporator drain pan drain trap has been
primed with water.

18. Turn on power to the unit at the disconnect switch.
Note: Units include one blower door switch per access
door (one on B- and C-Cabinet, two on D-Cabinet) that are
factory installed inside the blower access section door(s).
When a blower section door is opened, the switch is
opened and interrupts power to the low voltage circuit and
de-energizes the blower motor controller. D-Cabinet units
also have the same switches on the evaporator/hot gas
reheat coil access sections.

19. Check the Carel microprocessor controller and supply fan
blower motor for electrical operation. If the unit is equipped
with the optional building power exhauster module (with or
without energy recovery), check the blower motor for
electrical operation. If these do not function, recheck the
wiring diagram. Check to ensure that none of the Control
Options (for example, smoke detector, etc.) have tripped.

20. Check to make sure that the damper(s) operate properly
without binding.

21. Check that the supply power wiring is wired with the
correct phase rotation. For units equipped for dual power
supply sources, correct phase rotation must be verified on
both the main feed and the auxiliary feed. Incorrect phase
rotation can damage the equipment. Check the phase
rotation as follows:

• For units equipped with single speed motor
starters on the supply fan: Check the blower wheel

for proper direction of rotation when compared to the
air flow direction arrow on the blower housing. Blower
wheel rotation, not air movement, must be checked as
insufficient air will be delivered if the blower wheel is
running backwards. If the blower wheel is rotating in
the opposite direction, the phase reversal must be
corrected by changing the incoming power feed legs at
the supply to the unit, NOT the individual components
on the unit. Recheck for proper rotation.

• For units equipped with a variable frequency drive
on the supply fan: The VFD will correct the phase

rotation for the supply fan, but will not correct the phase
rotation for the rest of the unit, therefore observing the
supply blower wheel rotation direction is not an
accurate indicator of correct phase rotation. Scroll
compressors will only compress in one rotational
direction. Verification of proper rotation direction is
made by observing that suction pressure drops and
discharge pressure rises when the compressor is
energized. Reverse rotation will result in no pressure
differential as compared to normal values. There is no
negative impact on durability caused by operating the
compressors in the reversed direction for a short period
of time (under one hour) but should not be allowed to
operate longer than the time it takes to verify rotation.
If the compressor is rotating in the opposite direction,
the phase reversal must be corrected by changing the
incoming power feed legs at the supply to the unit,
NOT at the compressor. Recheck for proper rotation.

22. Check the blower speed (rpm). Refer to Blower
Adjustments for modification.

23. Check the motor speed (rpm).

24. Check the motor voltage. On three phase systems, check to
make sure all legs are in balance.

25. Check the motor amp draw to make sure it does not exceed
the motor nameplate rating. Check all legs to ensure system
is balanced.

26. For units equipped for dual power supply sources, the unit
should be started separately on the main power feed and
again on the auxiliary power feed to verify proper unit and
control operation.

Note: Units equipped for dual power supply sources have the
unit power wiring separated into two circuits as follows:

Circuit #1

• Compressors

• Condenser fans

• Electric heating section (if applicable).

• Energy recovery wheel (if applicable)

Circuit #2

• Main unit controller

• Supply fan

• Dampers

• Gas heating section (if applicable)

• Exhaust fan (if applicable)

• Energy recovery wheel bypass damper (if applicable)

When operating in a full power state with the main power
feed, both Circuit #1 and Circuit #2 should be powered.
When operating in a low power state with the auxiliary power
feed, only Circuit #2 should be powered.

Blower Adjustments

The units are designed for ease of airflow adjustments, within a
range, for field balancing against actual external static pressure
conditions. If the static pressure external to the unit is above
or below the original design point for the unit, the blower will
deliver an airflow volume that is lower or higher than required.
When equipped with the building exhaust option (with or
without energy recovery), the air balancing must be performed
for both the main unit supply fan, as well as the exhaust fan.

The blower speed (supply and/or exhaust blowers) may be
adjusted to achieve the desired air volume, provided:

• The allowable temperature rise range and the maximum
supply air temperature for heating is not exceeded as
shown in Table 18.1, and

• The airflow is within the allowable limits shown on the
serial plate for both heating and cooling, and

• The total static pressure does not exceed the limit shown
on the unit serial plate, and

• It is within the range of adjustability for the unit, and

• The motor amp draw must not exceed the motor

nameplate rating.

The blower speed adjustment method is dependant on the
following configurations:

• Direct Drive where the blower is driven directly by the
motor as seen in Figure 18.1. This is the current
standard supply fan configuration for all units.

• Belt Drive where the blower is driven by the motor with a
belt and sheaves as seen in Figure 18.2. This is the
current standard exhaust fan configuration (if equipped)
for all units. It was also used on supply fans for units
shipped before 2018.

Once the blower/motor configuration of the unit is determined,
follow the appropriate instructions in the sections on the
following pages.

17MCP15-500.7

START-UP PROCEDURE - CONTINUED

Figure 18.1 - Direct Drive Blower Example

Direct Driven Blower

(dual blower shown)

Figure 18.2 - Belt Drive Blower Example

Motor Sheave
(adjustable)

Blower Sheave
(non-adjustable)

Automatic Belt
Tensioner

Blower Adjustments – Direct Drive Fans

All direct drive supply fan speed adjustments can be performed
with the Modine Control System programmable microprocessor
controller. There are two ways to access the menus:

1. Using the user interface on the main unit controller.

2. Using the pGD1 Digital Display/Interface Module.

For guidance on either method above, refer to the latest
revision of the following documents for additional warnings,
cautions, controller location, instructions, and menu navigation:

• ControlsManual,MCP15-525.

• pGD1DigitalDisplay/InterfaceModuleInstallation

Instructions, MCP15-543.

The blower adjustments are made as follows:

1. Ensure unit is running at the maximum airflow setting for
the control type selected. For example, if the unit has
Multi-Speed or Variable Speed fan control, ensure the unit
is operating at the highest speed setting.

2. On the keypad navigate to menu “G. Service -> f.
SERVICE SETTINGS”. At this menu, you will be prompted
to enter the Service password of 1500.

3. Navigate to “c. Control Settings” and scroll to the “Supply
Fan Control (CS6)” screen. See Figure 18.3.

Table 18.1 - Allowable Temperature Rise Range and

Maximum Supply Air Temperature

Casing

Size

B

C

D

Heat
Type Rating

(for formula)

1 A, B, C, D 1.00 N 1 - 100°F 100°F

F, G, H, J, K 0.81

2 or 3

2 or 3

2 or 3

R, S, T 0.94 N 30 - 100°F 100°F

1 A, B, C, D, E 1.00 N 1 - 100°F 100°F

J 0.81 N 30 - 75°F

K, L, M 0.81

U, V 0.81

1 A, B, C, D, E 1.00 N 1 - 100°F 100°F

K 0.81 L 30 - 75°F

L, M, Q 0.81

1, 4

2, 3, 5 H 60 - 120°F

Eff

0.81

Temp Rise

Allowable

Temp Rise

Range

L 30 - <70°F
H 70 - 100°F

L 30 - <70°F
H 70 - 100°F
L 30 - <70°F
H 70 - 100°F

L 30 - <70°F
H 70 - 100°F
H 70 - 120°F

Max Supply

Air TempDigit 6 Digit 17 Digit 18 Digit 19

130°F

130°F

100°F

130°F

Figure 18.3 - Control Settings Screen CS6

4. Adjust the Air Balance Adj parameter up or down to obtain
the design airflow given the actual static pressure.

5. In the event you are unable to increase or decrease the
motor speed to the desired air balance please consult your
factory representative.

6. Check the motor amps to ensure the maximum motor amp
rating is not exceeded. For units equipped with a VFD,
measure the amps at the incoming lines to the motor. If
the unit has dual supply fans, measure each motor
individually. Verify airflow volume and repeat steps above
for further adjustment.

7. If equipped with gas heat, turn on the gas and initiate
burner operation. For guidance, refer to the Controls
Manual.

8. Verify the temperature rise and supply air temperature of
the heating section do not fall outside the range or exceed
the maximums shown in Table 18.1. Airflow can be
approximated with the following formula:

CFM = (Input Btu/hr x Eff) / (1.08 x Temp Rise)
where Eff (Efficiency) is determined from Table 18.1

18 MCP15-500.7