Magic-Pak MHP4 Series User manual

507861-01 Issue 1927 Page 1 of 17
Save these instructions for future reference
INSTALLATION AND MAINTENANCE INSTRUCTIONS
MHP4 Series
Self-Contained Heat Pump
Manufactured By
Allied Air Enterprises LLC
A Lennox International Inc. Company
215 Metropolitan Drive
West Columbia, SC 29170
This is a safety alert symbol and should never be ignored. When you see this symbol on labels or in
manuals, be alert to the potential for personal injury or death.
Improper installation, adjustment, alteration, service, or
maintenance can cause injury or property damage. Refer
to this manual. For assistance or additional information,
consult a qualied installer or service agency.
WARNING
Table of Contents
Installation ...................................................................1
Operation.....................................................................9
Maintenance..............................................................11
Accessories ...............................................................12
Wiring Diagrams........................................................14
The installation of this appliance must conform to the requirements of the National Fire Protection Association; the National
Electrical Code, ANSI/NFPA No. 70 (latest edition) in the United States; the Canadian Electrical Code Part 1, CSA 22.1
(latest edition) in Canada; and any state or provincial laws or local ordinances. Local authorities having jurisdiction should
be consulted before installation is made. Such applicable regulations or requirements take precedence over the general
instructions in this manual.
CAUTION
(P) 507861-01
*P507861-01*
Installation
These units are not approved for mobile home
applications. Such use could result in property damage,
personal injury, or death.
WARNING
General
These instructions explain the recommended method of
installation of the MHP4 electric cooling unit and associated
electrical wiring.
This unit is designed and approved for use as a self-
contained air-to-air air conditioning system with optional
CLIMATE GUARD™ coated coils.
These instructions, and any instructions packaged with
mating components and/or accessories, should be carefully
read prior to beginning installation. Note particularly any
CAUTIONS or WARNINGS in these instructions and all
labels on the units.
These instructions are intended as a general guide only,
for use by qualied personnel and do not supersede any
national or local codes in any way. Compliance with all local,
state, provincial, or national codes pertaining to this type of
equipment should be determined prior to installation.

Page 2 of 17 507861-01Issue 1927
Units that comply with the maximum cabinet leakage 2% of
rated airow requirements of ANSI/ASHRAE 193 (complies
with IECC 2015) are identied on the rating plate.
Installation and servicing of air conditioning equipment
can be hazardous due to internal refrigerant pressure
and live electrical components. Only trained and
qualied service personnel should install or service
this equipment. Installation and service performed by
unqualied persons can result in property damage,
personal injury, or death.
WARNING
For your safety, do not store or use gasoline or other
ammable vapors and liquids in the vicinity of this or any
other appliance. Such actions could result in property
damage, personal injury, or death.
WARNING
The unit must be installed with approved wall sleeve
and grille accessories for safe operation. Improper
installations could result in property damage, personal
injury, or death.
WARNING
Inspection
Upon receipt of equipment, carefully inspect it for possible
shipping damage. If damage is found, it should be noted
on the carrier’s freight bill. Take special care to examine
the unit inside the carton if the carton is damaged. File a
claim with the transportation company. If any damages
are discovered and reported to the carrier do not
install the unit, as claim may be denied.
Check the unit rating plate to conrm specications
are as ordered.
Limitations
The unit should be installed in accordance with all national
and local safety codes.
Limitations of the unit and appropriate accessories must
also be observed.
The outdoor fan is designed to operate against no more
than .10” w.c. static pressure.
Minimum and maximum operation conditions must be
observed to assure maximum system performance
with minimum service required. Refer to Table 1 for the
application limitations of the unit.
Table 1. Application Limitations
Outdoor Ambient Air Temperature °F
Minimum DB Maximum DB
Cool Cool Heat
65 115 75
Indoor Ambient Air Temperature °F
Minimum Maximum
DB/WB DB DB/WB DB
Cool Heat Cool Heat
62/57 50 90/72 80
DB = Dry Bulb
WB = Wet Bulb
Location
The unit must be installed with approved wall sleeve
and grille accessories for safe operation. Improper
installations could result in property damage, personal
injury, or death.
WARNING
For information on wall sleeves and grille accessories, see
the Accessories section.
The design is certied for thru-the-wall or up-to-the wall
(inside wall) installation only. The interior portions of
the unit may be surrounded by a closet with clearances
to combustible material held to 0” at the sides, top, and
front of the plenum. All servicing and cleaning of the unit
can be performed from the front. If installed in a closet
or utility room, provide 25” clearance in front for service
if the door to the room is not in line with the front of the
unit (see Figure 1). Accessibility clearances must take
precedence over re protection clearances.

507861-01 Issue 1927 Page 3 of 17
Figure 1. Minimum Clearances
ExteriorWall
Wall Sleeve
(one each side)
InteriorWall
Clearances*
MountingStrap
(one each side)
3/4" Plywood Riser
Floor
Front of Unit
Sill Plate
4" Min.
Unit must be supported by platform, which must be
level with sill plate of hole in exterior wall.
Platform (field supplied) -
Side View
Clearance to combustible materials is 0” at the side, top, and front of plenum. If accessibility clearances are greater
than clearances to combustibles, accessibility clearances take precedence.
The front of the unit must be accessible for service. If the unit is enclosed, providing a door or access panel opposite
the front of the unit is the preferred method of providing access. The door or access panel must be at least 30” wide
(centered on the unit) and as tall as the unit.
IMPORTANT
The unit must be installed with approved wall sleeve and grille
accessories for safe operation. Improper installations could result
in property damage, personal injury, or death.
Cabinet
Height
Minimum Unit Clearance
Front* Sides
44” or 48” 4” 1”
56” or 68” 5”
* Listed clearance is using front return with
no front return duct installed. If a return
duct (top or front) is installed, enough
clearance must be provided for the drain
trap installation.
Top View
Supply Duct
Opening
Clearance to
Front of Unit*
Front of Unit
1”
Min.
1”
Min.
Optional Front
Return Opening
May be used with or
without attached ductwork
Return Duct
Opening

Page 4 of 17 507861-01Issue 1927
The outside of the unit may be ush with the face of
the exterior wall, and it should not be obstructed with
trees, landscape materials, or building structure. Unit
can be installed recessed with appropriate wall sleeve
accessories. There is no minimum clearance required on
locating the unit to an interior corner of a building.
If the unit is installed in a residential garage, it must be
located or protected to avoid physical damage by vehicles.
The unit must be installed so that no electrical components
are exposed to water.
This unit must be installed level to allow for proper
drainage of the unit base pan and indoor drain pan.
CAUTION
Wall Sleeve and Louver Grille Installation
Refer to installation instructions included with the wall
sleeve kit and the louver grille kit along with Figure 2 for
guidance in assembling and installing the wall sleeve and
louver grille.
The sleeve is not intended as the sole support for
the unit. An additional support must be provided for
adequate support (see Figure 2).
CAUTION
Installing and Securing Unit to Wall Sleeve
1. Make sure the gaskets attached to the sleeve are not
damaged.
2. Verify divider panel is positioned properly. Refer to
Table 2 for wall sleeves that allow for multiple divider
panel locations.
ASLEEVE**-2 ASLEEVE**-5 Orientation
of Flange
Model Two
Positions
Three
Positions
MHP4-11-09,12 Lower Lower Down
MHP4-11-18
UpMHP4-11-24, 30 Upper Middle
MHP4-11-36 N/A Upper
Table 2.
Figure 2. Wall Sleeve and Louver Kit Installed
NOTE: Platform must be constructed so that it is level with sill plate of wall opening.

507861-01 Issue 1927 Page 5 of 17
3. Place the MHP unit into the wall sleeve. Lift leading
end of unit and walk unit onto the sleeve. Once in
the sleeve, lower the unit into position. This prevents
damage to the base pads. Assure that the unit is level
and completely seated against the gaskets on the wall
sleeve. The unit must be supported by a eld supplied
base platform.
Figure 3. Positioning Divider Panel
Flange Up Orientation
Flange Down Orientation
4. Use the two installation brackets to secure the unit to
the wall sleeve (see Figure 4). The units are shipped
with the brackets placed in the return air compartment.
Hook each bracket into the front edge of the wall sleeve
side. Position the bracket so it can be bent around the
front corner of the unit. Remove one of the two screws
in that position on the unit. Line up one of the holes in
the installation bracket with the screw hole and attach
the bracket to the unit with that screw. Make sure to
fasten tight enough that the seal is maintained. Trim
o󰀨 excess bracket if applicable.
Figure 4. Securing Unit
Installation
Brackets
Remove and replace screw to secure bracket
(one each side)
Do not screw into the side of the drain pan, or into the
indoor coil or heat strip.
CAUTION
5. Inspect the t up of the unit to the wall sleeve. Verify
that the gaskets of the wall sleeve make a complete
seal to the unit paying particular attention to top and
bottom corners of unit to sleeve seal. Caulk if needed.
Ductwork
Ductwork should be designed and sized according to the
methods in Manual Q of the Air Conditioning Contractors
of America (ACCA).
Check unit air supply outlet for debris before making
ductwork connections.
It is recommended that supply and return duct connections
at the unit be made with exible joints. If exible ducts are
used, a 6” sheet metal starter collar is required.
The supply and return air duct systems should be designed
for the CFM and static requirements of the job (see Table
3). They should not be sized to match the dimensions
of the duct connections on the unit. The return duct
should be sealed to the unit casing and terminate outside
the space containing the unit.
Optional Front Return
As shipped, units are congured for attaching supply and
return ductwork to the top of the unit. Return air may be
brought in through the optional front return opening. To
open the optional front return and close o󰀨 the top return
opening, perform the following steps.
1. Rotate knob to release lter access panel and remove
panel.
a. For all units except 3-ton models, position lter
access panel to close o󰀨 top return opening.
Secure at rear using two sheet metal screws.
Secure in front using knob. See Figure 5.
b. For 3-ton models, eld fabricate a sheet metal
panel to close o󰀨 the top return opening.
2. Seal panel to top of unit with tape or mastic.
NOTE: If ductwork is attached to the optional front return
opening, provisions to service unit lter must be provided.
Figure 5. Secure Filter Access Panel

Page 6 of 17 507861-01Issue 1927
Airow Performance as a Function of External Static Pressure
Model
Indoor Blower Speed
0.1 “w.c. 0.2 “w.c. 0.3 “w.c. 0.4 “w.c. 0.5 “w.c.
SCFM Watts SCFM Watts SCFM Watts SCFM Watts SCFM Watts
*MHP4-11-091*P
TAP 1 (FAN) 365 28 330 31 275 35 225 38 180 41
TAP 2 (COOL/HP)†375 28 325 32 275 35 N/A N/A N/A N/A
TAP 3 (COOL/HP) N/A N/A N/A N/A 395 54 370 58 330 62
3 kW
TAP 4 (AUX HEAT)* 515 55 485 58 450 62 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 600 73 570 78 545 84 515 88 475 92
5 kW
TAP 4 (AUX HEAT)* 570 69 545 73 515 77 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 660 92 635 98 605 104 580 109 550 114
*MHP4-11-121*P
TAP 1 (FAN) 365 28 330 31 275 35 225 38 180 41
TAP 2 (COOL/HP)†490 50 460 55 420 59 N/A N/A N/A N/A
TAP 3 (COOL/HP) N/A N/A 555 77 525 82 495 86 460 91
3 kW
TAP 4 (AUX HEAT)* 515 55 485 58 450 62 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 600 73 570 78 545 84 515 88 475 92
5 kW
TAP 4 (AUX HEAT)* 570 69 545 73 515 77 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 660 92 635 98 605 104 580 109 550 114
*MHP4-11-181*P
TAP 1 (FAN) 365 32 335 35 280 39 235 42 175 46
TAP 2 (COOL/HP)†615 103 590 108 555 112 530 117 500 121
TAP 3 (COOL/HP) 700 135 670 141 640 146 615 151 590 157
3 kW
TAP 4 (AUX HEAT)* 615 93 590 97 555 101 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 715 127 685 134 655 140 630 146 600 151
5 kW
TAP 4 (AUX HEAT)* 665 110 635 114 605 118 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 750 148 725 154 700 160 675 166 650 171
7 kW
TAP 4 (AUX HEAT)* 725 137 705 144 675 150 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 825 194 800 200 780 205 755 209 725 213
10 kW
TAP 4 (AUX HEAT)* 750 148 725 154 700 161 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 860 213 832 219 805 224 780 228 750 232
*MHP4-11-241*P
TAP 1 (FAN) 460 43 420 47 380 51 350 54 290 59
TAP 2 (COOL/HP)†815 150 785 161 760 165 740 172 715 178
TAP 3 (COOL/HP) 885 201 860 208 835 213 805 217 785 220
5 kW
TAP 4 (AUX HEAT)* 800 146 775 152 750 157 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 905 201 880 207 855 212 825 216 800 219
7 kW
TAP 4 (AUX HEAT)* 855 174 830 179 800 183 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 955 227 930 231 900 235 875 239 850 243
10 kW
TAP 4 (AUX HEAT)* 855 174 830 179 800 183 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 955 227 930 231 900 235 875 239 850 243
N/A: Do not operate unit using this blower speed at this external static pressure.
† As shipped speed for Cooling operation. Blower speed must be eld adjusted to Speed Tap 3 for higher duct static applications.
* As shipped speed for Heating operation. Blower speed must be eld adjusted to Speed Tap 5 for higher duct static applications.
Table 3. Blower Performance (208V or 230V)

507861-01 Issue 1927 Page 7 of 17
Airow Performance as a Function of External Static Pressure
Model
Indoor Blower Speed
0.1 “w.c. 0.2 “w.c. 0.3 “w.c. 0.4 “w.c. 0.5 “w.c.
SCFM Watts SCFM Watts SCFM Watts SCFM Watts SCFM Watts
*MHP4-11-301*P
TAP 1 (FAN) 590 43 535 48 430 55 380 60 315 65
TAP 2 (COOL/HP)†1040 161 1005 169 970 177 935 185 900 193
TAP 3 (COOL/HP) 1135 201 1105 211 1070 220 1040 229 1010 237
5 kW
TAP 4 (AUX HEAT)* 1075 151 1040 159 1005 168 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 1165 181 1135 193 1100 205 1065 216 1025 225
7 kW
TAP 4 (AUX HEAT)* 1075 151 1040 159 1005 168 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 1165 181 1135 193 1100 205 1065 216 1025 225
10 kW
TAP 4 (AUX HEAT)* 1075 151 1040 159 1005 168 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 1165 181 1135 193 1100 205 1065 216 1025 225
*MHP4-11-361*P
TAP 1 (FAN) 680 61 630 68 575 74 525 79 460 86
TAP 2 (COOL/HP)†1235 260 1200 272 1165 284 1135 295 1100 305
TAP 3 (COOL/HP) 1315 304 1280 316 1250 330 1215 342 1180 354
5 kW
TAP 4 (AUX HEAT)* 1240 232 1205 248 1170 262 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 1340 283 1290 300 1260 315 1230 328 1200 338
7 kW
TAP 4 (AUX HEAT)* 1240 232 1205 248 1170 262 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 1340 283 1290 300 1260 315 1230 328 1200 338
10 kW
TAP 4 (AUX HEAT)* 1240 232 1205 248 1170 262 N/A N/A N/A N/A
TAP 5 (AUX HEAT) 1340 283 1290 300 1260 315 1230 328 1200 338
N/A: Do not operate unit using this blower speed at this external static pressure.
† As shipped speed for Cooling operation. Blower speed must be eld adjusted to Speed Tap 3 for higher duct static applications.
* As shipped speed for Heating operation. Blower speed must be eld adjusted to Speed Tap 5 for higher duct static applications.
Table 3. Blower Performance (208V or 230V)
Air Filter
All indoor return air must be ltered. A washable lter is
furnished with the unit, located in the return air compartment.
If the optional front return opening is used and a duct is
installed, provisions must be made to accommodate lter
servicing. If a lter is installed at a separate central return
location, then the factory furnished lter must be removed
from the unit.
The lter should be cleaned at least three times during
each of the heating and cooling seasons, or more
frequently if unusual conditions are encountered. To clean
the washable lter, shake lter to remove excess dirt and/
or use a vacuum cleaner. Wash lter in soap or detergent
water and replace after lter is dry. It is not necessary to oil
the lter after washing.
The washable lter may be replaced with a disposable
lter. Table 4 lists lter sizes that t the unit.
If an installation is made in which it is more desirable to
mount the lter exterior to the unit, in the return duct work
or elsewhere, the washable lter can be used or replaced
with a disposable lter. If a disposable lter is used, use the
information provided in Table 5 when sizing the disposable
lter.
Model Number Filter Size
(in.)
*MHP4-11-09*
*MHP4-11-12* 18 x 20 x 1
*MHP4-11-18* 20 x 20 x 1
*MHP4-11-24*
*MHP4-11-30* 22 x 24 x 1
*MHP4-11-36* 22 x 28 x 1
Table 4. Filter Sizes

Page 8 of 17 507861-01Issue 1927
Model Number Filter Area
(in2)
*MHP4-11-09*
*MHP4-11-12* 265
3MHP4-11-18*
5MHP4-11-18* 310
7MHP4-11-18*
10MHP4-11-18* 360
*MHP4-11-24* 400
*MHP4-11-30* 515
*MHP4-11-36* 600
Table 5. Minimum Required Surface Area for
Disposable Filters
Condensate Drain
Provisions must be made to properly drain the indoor and
outdoor drain pans of this appliance.
Indoor drain and outdoor drain connection: 3/4” NPT to
3/4” PVC tting (schedule 40 minimum). Both drains must
be trapped as shown in Figure 6. The drain line should
pitch gradually downward at least 1” per 10’ of horizontal
run to an open drain.
Figure 6. Condensate Drain Installation
If local codes require the use of metal condensate lines,
do not thread metal ttings into the unit drain pans. Thread
a PVC tting into the unit drain pans and make the eld
connection to the PVC tting.
NOTE: MHP units are designed with a redundant drain
system to handle condensate without the need for a
secondary or emergency drain pan. Should the indoor
coil condensate drain system fail, all water is contained
within the unit and the ow is directed into the unit base
pan. From there it will drain into the condensate riser.
If for some reason the water cannot drain into the main
condensate riser, all water is contained in the unit, and the
design will allow drainage out through the wall sleeve and
louver assembly to the outside of the building.
Use thread sealant on the threaded ttings. Install
threaded ttings by hand only. Do not over torque the
ttings.
Do not thread metal condensate ttings to unit drain
pans.
CAUTION
Outdoor Ventilation Air
Units are tted with a panel that seals the return air
compartment at the outdoor air duct. If introduction of
outdoor air is desired, installers can replace the factory-
installed panel with the provided auxiliary panel by removing
screws holding both the factory and auxiliary panels, and
then replacing with the auxiliary panel and screw.
NOTE: If outdoor ventilation air is introduced, the quantity
of air and conditions of this air must be accounted for in the
load calculations for the unit installation.
The auxiliary panel includes nine knockouts to congure
air ow to installation requirements. Use Table 6 and
Figure 7 to determine which knockouts to remove from the
auxiliary panel in order to achieve the desired air ow. Use
a at head screw driver to remove the knockouts. Set the
factory-installed panel aside for possible future changes.
Outdoor Ventilation Air
(CFM)
*MHP4-11-09* *MHP4-11-12* *MHP4-11-18* *MHP4-11-24* *MHP4-11-30* *MHP4-11-36*
Nominal
Indoor Airow 350 475 600 800 1025 1200
Number of Openings
#1 Only 6 11 13 18 20 23
#1 and #2 10 17 21 24 28 31
#1 thru #3 17 22 26 32 36 41
#1 thru #4 23 28 35 41 45 49
#1 thru #5 31 34 42 50 55 60
#1 thru #6 35 41 49 57 66 72
#1 thru #7 41 49 56 68 80 86
#1 thru #8 46 56 64 78 88 98
#1 thru #9 50 60 73 90 100 112
Table 6.

507861-01 Issue 1927 Page 9 of 17
Operation
Sequence of Operation
Upon initial “power up” to unit, there is a 3-minute time delay
to the compressor contactor (R to Y). Any 24V interrupt (R,
C) to the defrost control will initiate the 3-minute delay to
the contactor.
Cooling
When the thermostat is in the cooling mode, the O circuit
is powered which energizes the reversing valve. Upon
cooling demand, the thermostat closes circuit R to Y and
G. Closing R to Y closes the unit contactor, starting the
compressor and outdoor fan, and signaling the indoor
blower to run at cooling speed. Upon satisfying cooling
demand, the thermostat will open the above circuits and
open the main contactor, stopping the compressor and
outdoor fan. The unit is equipped with a blower OFF delay;
the blower will continue to operate for a xed 90 seconds
after the thermostat is satised.
Heating
Upon heating demand, the thermostat closes circuit R to
Y, which closes the unit contactor, starting the compressor
and outdoor fan. The reversing valve is not energized in
the heating mode. The Y signal from the thermostat brings
the indoor blower on at heat pump speed. The second
stage of the thermostat closes circuit R to W, which closes
the unit sequencers, bringing the auxiliary electric heat on.
The W signal from the thermostat brings the indoor blower
on at electric heat speed. Upon satisfying heating demand,
the thermostat opens the above circuits and stops unit
operation.
The unit is equipped with a blower OFF delay; the blower
will continue to operate for a xed 90 seconds (heat pump)
or 120 seconds (electric heat) after the thermostat is
satised.
NOTE: The 7.2 and 10 kW heats strips oer a W1 and
W2 thermostat connection. Taking advantage of the two
heat strip circuits requires a 3-stage thermostat (Y for heat
pump, W1 for electric heat stage 1, and W2 for electric
The location of fresh air capable models must conform to
the requirements of National Fire Protection Association
NFPA No. 54 in regards to proximity of forced air inlets
to ue gas terminals. Improper installation could result
in personal injury or death.
WARNING
Figure 7. Auxiliary and Factory Panel for Outdoor Air
Duct
Factory panel
Outdoor
Air Duct
Auxillary panel
with knockouts
1
2
3
4
5
6
7
8
9
Thermostat
The room thermostat should be located on an inside
wall where it will not be subject to drafts, sun exposure,
or heat from electrical xtures or appliances. Follow
manufacturer’s instructions enclosed with the thermostat
for general installation procedures. Color-coded insulated
wires (#18 AWG) should be used to connect the thermostat
to the unit.
Electrical Connections
All wiring must be done in accordance with the National
Electrical Code (NEC), ANSI/NFPA No. 70 (latest edition);
Canadian Electrical Code CSA C22.2 Part 1 (latest edition);
or local codes, where they prevail. Any alteration of internal
wiring will void certication and warranty.
Units are factory wired for a 230 volt power supply. If power
supply is 208 volts, it will be necessary to change a wire
connection on unit transformer from 240 volt terminal to
208 volt terminal as shown on the wiring diagram.
Use wiring with a temperature limitation of 75°F minimum.
Run the 208 or 230 volt, single phase, 60 hertz electric
power supply through a fused disconnect switch to the
control box of the unit and connect as shown in the unit’s
wiring diagram.
The unit must be electrically grounded in accordance with
local codes or, in the absence of local codes, with the
National Electrical Code ANSI/NFPA No. 70 (latest edition)
or CSA C22.2 Part 1 (latest edition).
Power supply to the unit must be NEC Class 1 and must
comply with all applicable codes. A fused disconnect switch
should be eld provided for the unit. The switch must be
separate from all other circuits. If any of the wire supplied
with the unit must be replaced, replacement wire must be
of the type shown on the wiring diagram. Electrical wiring
must be sized to minimum circuit ampacity marked on the
unit. Use copper conductors only. Each unit must be
wired with a separate branch circuit and be properly fused.
NOTE: Some MHP4 models require two separate power
supply circuits. See the unit wiring diagrams and rating
plates for specications.

Page 10 of 17 507861-01Issue 1927
heat stage 2). If a 2-stage thermostat is used, “pigtail” W1
and W2 wires together when connecting the thermostat
wires at the unit.
Defrost Cycle
If the outdoor ambient conditions are such that frost forms
on the outdoor coil, the defrost control monitors the need
for, initiates, and terminates defrost cycles as necessary to
maintain system performance. The defrost control is time/
temperature initiated and temperature terminated with
a maximum defrost time (time-out) of 14 minutes. Time
between defrost cycles is preset at 90-minute intervals at
the factory, but can be eld adjusted between 30, 60, or 90
minutes. To eld adjust time between defrost cycles, place
defrost time plug in the proper position (see Figure 9).
Figure 8. Defrost Control
24V TERMINAL
STRIP
CONNECTIONS
DIAGNOSTIC
LEDS
HIGH PRESSURE
SWITCH
TEST
PINS
REVERSING
VALVE
DEFROST
THERMOSTAT
LOW PRESSURE
SWITCH SERVICE LIGHT
CONNECTIONS
FIELD SELECT
DEFROST INTERVAL
TIMING PINS
30
TEST
90
60
P1
Figure 9. Defrost Interval Timing Jumper
Defrost control will initiate a defrost cycle if the time period
has elapsed and the defrost sensor sees a temperature
below freezing. At the start of a defrost cycle, the defrost
control will energize the reversing valve solenoid, shifting
the reversing valve and de-energizing the outdoor fan.
The defrost control will also energize auxiliary heat for
increased comfort during defrost. The unit will remain in
defrost until the defrost sensor has determined that the
frost has been removed from the coil or a 14-minute time
period has elapsed.
The defrost control is also equipped with a set of pins to aid
in the troubleshooting of the defrost system (see Figure 9).
The following is a brief outline of the testing of the defrost
system.
1. Defrost sensor must be closed, 32°F or below. If
temperatures are such that the switch will not close,
jumper between defrost sensor terminals on the
defrost control.
2. Start system in heating operation.
3. Place the defrost pin jumper on the test pins for a brief
second, then place back on the proper defrost time
setting (30, 60, or 90). This will speed up defrost time
interval as shown in Table 7.
Defrost Control Setting Defrost Test Cycle Time
30 minutes 7 seconds
60 minutes 14 seconds
90 minutes 21 seconds
Table 7. Defrost Test Cycle Time
The reversing valve will then shift to defrost mode and
the outdoor fan should stop. After 2 seconds of defrost
operation, the reversing valve should shift back to heating
operation and the outdoor fan should start.
Diagnostic LEDs
The state (O󰀨, On, Flashing) of two LEDs on the defrost
board (DS1 [Red] and DS2 [Green]) indicate diagnostics
conditions that are described in Table 8.
Mode Green LED (DS2) Red LED (DS1)
No power to control O󰀨 O󰀨
Normal operation /
power to control Simultaneous slow ash
Timed lockout Alternating slow ash
Low pressure switch
fault O󰀨 Slow ash
Low pressure switch
lockout O󰀨 On
High pressure switch
fault Slow ash O󰀨
High pressure switch
lockout On O󰀨
Table 8.

507861-01 Issue 1927 Page 11 of 17
Maintenance
Disconnect all electrical power to the unit before
conducting any maintenance procedures. Failure to
disconnect the power could result in personal injury or
death.
WARNING
Periodic inspection and maintenance normally consists of
changing or cleaning lters and (under some conditions)
cleaning the coils.
Filter
Inspect the lter once a month. Replace disposable lter or
clean the washable lter as necessary (a minimum of three
times each heating or cooling season is recommended).
To clean the washable lter, shake lter to remove excess
dirt and/or use a vacuum cleaner. Wash lter in soap or
detergent water and replace after lter is dry. It is not
necessary to oil the lter after washing.
Motors
The indoor and outdoor fan motors are permanently
lubricated and require no maintenance.
Outdoor Coil
Foreign material should not be allowed to accumulate on
the outdoor coil surface or other parts in the air circuit.
Cleaning should be as often as necessary to keep the coil
clean. To clean the coil, remove the lower access panel
and blow out debris by using compressed air or water. Be
sure power to unit is shut o󰀨 before using water to
clean the coil.
Care should be used when cleaning the coils so that
the coil ns are not damaged.
Outdoor Base Drain
Foreign material should not be allowed to clog the drain
hole. Inspect and clear drain opening prior to heating
season.

Page 12 of 17 507861-01Issue 1927
Accessory Nomenclature
Magic-Pak Unit
*MHP4-11-091*P *MHP4-11-121*P *MHP4-11-181*P *MHP4-11-241*P *MHP4-11-301*P *MHP4-11-361*P
Polypropylene Louvers
Polypropylene Louver Kit - White (29” Height ) ALVRPWHT-1 • • •
Polypropylene Louver Kit - White (33” Height) ALVRPWHT-2 • • • • •
Polypropylene Louver Kit - Sandstone (29” Height) ALVRPSAN-1 • • •
Polypropylene Louver Kit - Sandstone (33” Height) ALVRPSAN-2 • • • • •
Polypropylene Louver Kit - Beige (29” Height) ALVRPBGE-1 • • •
Polypropylene Louver Kit - Beige (33” Height) ALVRPBGE-2 • • • • •
Polypropylene Louver Kit - Taupestone (29” Height) ALVRPTPST-1 • • •
Polypropylene Louver Kit - Taupestone (33” Height) ALVRPTPST-2 • • • • •
Aluminum Louvers
Extruded Aluminum Louver Kit (29” Height) ALVRAL-1 • • •
Extruded Aluminum Louver Kit - Custom Color (29” Height) ALVRAL-1P • • •
Extruded Aluminum Louver Kit (33” Height) ALVRAL-2 • • • • •
Extruded Aluminum Louver Kit - Custom Color (33” Height) ALVRAL-2P • • • • •
Extruded Aluminum Louver Kit (45” Height) ALVRAL-3 •••
Extruded Aluminum Louver Kit - Custom Color (45” Height) ALVRAL-3P •••
Extruded Aluminum Louver Kit (45” Height) ALVRAL-4 • • •
Extruded Aluminum Louver Kit - Custom Color (45” Height) ALVRAL-4P • • •
Impact Rated Louvers
Extruded Aluminum Louver Kit - Impact Rated (29” Height) ALVRALC-1 • • •
Extruded Aluminum Louver Kit - Impact Rated / Custom Color (29” Height) ALVRALC-1P • • •
Extruded Aluminum Louver Kit - Impact Rated (33” Height) ALVRALC-2 • • • • •
Extruded Aluminum Louver Kit - Impact Rated / Custom Color (33” Height) ALVRALC-2P • • • • •
Extruded Aluminum Louver Kit - Impact Rated (45” Height) ALVRALC-3 •••
Extruded Aluminum Louver Kit - Impact Rated / Custom Color (45” Height) ALVRALC-3P •••
Extruded Aluminum Louver Kit - Impact Rated (45” Height) ALVRALC-4 • • •
Extruded Aluminum Louver Kit - Impact Rated / Custom Color (45” Height) ALVRALC-4P • • •
Table 9. Accessories
Accessories

507861-01 Issue 1927 Page 13 of 17
Maximum Wall
Thickness
C
A1
B
D
E
29 1/8
Required Wall Opening
29
Figure 10.
Wall Sleeve Nomenclature
Magic-Pak Unit Dimensions (in)
*MHP4-11-091*P *MHP4-11-121*P *MHP4-11-181*P *MHP4-11-241*P *MHP4-11-301*P *MHP4-11-361*P
A B C D E
6” Wall Sleeve Kit
for 29” Louver ASLEEVE6-1 • • • 6 29 16 16-5/8 29-1/8
for 33” Louver ASLEEVE6-2 • • • • • 6 32-3/4 16 16-5/8 32-7/8
for 45” Louver ASLEEVE6-5 • • • • • • 6 45 16 16-5/8 45-1/8
8” Wall Sleeve Kit
for 29” Louver ASLEEVE8-1 • • • 8 29 16 16-5/8 29-1/8
for 33” Louver ASLEEVE8-2 • • • • • 8 32-3/4 16 16-5/8 32-7/8
for 45” Louver ASLEEVE8-5 • • • • • • 8 45 16 16-5/8 45-1/8
10” Wall Sleeve Kit
for 29” Louver ASLEEVE10-1 • • • 10 29 16 16-5/8 29-1/8
for 33” Louver ASLEEVE10-2 • • • • • 10 32-3/4 16 16-5/8 32-7/8
for 45” Louver ASLEEVE10-5 • • • • • • 10 45 16 16-5/8 45-1/8
12” Wall Sleeve Kit
for 29” Louver ASLEEVE12-1 • • • 12 29 16 16-5/8 29-1/8
for 33” Louver ASLEEVE12-2 • • • • • 12 32-3/4 16 16-5/8 32-7/8
for 45” Louver ASLEEVE12-5 • • • • • • 12 45 16 16-5/8 45-1/8
Thru-The-Wall-Sleeve-Kit ASLEEVE-3 • • N/A 45 16 16-5/8 45-1/8
Table 10. Wall Sleeves
The unit must be installed with approved wall sleeve and grille accessories for safe operation. Improper installations
could result in property damage, personal injury, or death.
WARNING

Page 14 of 17 507861-01Issue 1927
Figure 11. Connection Diagram - MHP With Single Circuit Without Hard Start
#538014-01
Wiring Diagrams

507861-01 Issue 1927 Page 15 of 17
Figure 12. Connection Diagram - MHP With Dual Circuits Without Hard Start
#538014-02

Page 16 of 17 507861-01Issue 1927
Figure 13. Connection Diagram - MHP With Single Circuit and Hard Start Enabled
#538051-01

507861-01 Issue 1927 Page 17 of 17
Figure 14. Connection Diagram - MHP With Dual Circuit and Hard Start Enabled
#538051-02