Lennox Diplomat 10HP12 Owner's manual

SERVICE 10HP
UNIT
INFORMATION
Page 1 1994 Lennox Industries Inc.
Corp. 9427–L10
Replaces Corp. 9329–L4 Litho U.S.A.
10HP SERIES UNITS
The 10HP is a high-efficiency residential
split-system heat pump. Extra large outdoor coil,
coil circuiting and high outdoor coil air volume
result in a high SEER rating (minimum of 10.0).
10HP12 through 10HP48 units are designed for use
with an expansion valve or RFCIII system in the
indoor unit. 10HP60 units are designed for use with
an expansion valve only in the indoor unit.
All compressors are hermetically sealed for
trouble-free operation and long service life.
Compressor components are spring mounted within
the sealed housing. The compressor is installed in the
unit on resilient rubber mounts to assure quiet,
vibration-free operation. A built-in limit protects the
compressor from excessive current and temperatures.
10HP18 through 10HP60 models are furnished with
crankcase heaters as standard equipment. The heater
prevents liquid from accumulating in the compressor.
The heater is temperature-actuated and operates only
when required. A crankcase heater for 10HP12 units is
optional, but suction accumulator is factory installed.
Several models are available in sizes ranging from 1
through 5 tons.
This manual is divided into sections which discuss the
major components, refrigerant system, charging
procedure, maintenance, and operation sequence.
Canadian specifications are marked (CAN).
All specifications in this manual are subject to change.
SPECIFICATIONS
Model No. 10HP12 10HP18 10HP24 10HP30-1 10HP30-2
Net face a ea (sq ft )
12 6
12 6
12 6
14 7
Outdoor
N
et
f
ace area
(
sq.
f
t.
)
12
.
6
12
.
6
12
.
6
14
.
7
O
u
td
oor
Coil Tube diameter (in.) & no. of rows 3/8 — 1 3/8 — 1 3/8 — 1 3/8 — 1
Coil
Fins per inch 20 20 20 20
Diameter (in.) & no. of blades 20 — 3 20 — 3 20 — 3 20 — 3
Motor hp 1/6 1/6 1/6 1/6
Outdoor
F
Cfm 2630 2630 2630 2665
Fan Rpm 840 840 840 850
Watts 210 210 210 210
Full load amps 1.1
Refrigerant — 22 charge furnished 5 lbs. 3 oz. 5 lbs. 6 oz. 6 lbs. 2 oz. 7 lbs. 3 oz
Liquid line (o.d. in.) connection (sweat) 3/8  3/8 3/8 3/8
Vapor line (o.d. in.) connection (sweat) 1/2 5/8 5/8 3/4
Line voltage data – 60hz 208-230v—1ph
Compressor rated load amps 5.0 8.1 10.9 12.2 13.7
Rec. max. fuse or circuit breaker size (amps) 15 15 25 25 30
*Minimum circuit ampacity 7.4 11.3 14.8 16.4 18.2
*Refer to National Electric Code manual to determine wire, fuse and disconnect size requirements.
NOTE – Extremes of operating range are plus 10% and minus 5% of line voltage.
3/8 in. x 1/4 in. reducer furnished to adapt to 1/4 in. field fabricated line set.
 3/8 in. x 5/16 in. reducer furnished to adapt unit to 5/16 in. line set.

Page 2
SPECIFICATIONS (continued)
Model No. 10HP36 10HP36-4 10HP42 10HP48 10HP60
Net face area (sq ft )
Outer coil 14.7 14.7 20.0 20.0 20.0
Outdoor
N
e
t
f
ace area
(
sq.
ft
.
)
Inner coil 3.9 3.9 - - - - 6.3 19.0
Coil Tube diameter (in.) & no. of rows 3/8 — 1.3 3/8 — 1.3 3/8 — 1 3/8 — 1.3 3/8 — 2
Fins per inch 20 20 20 20 20
Diameter (in.) & no. of blades 20 — 3 20 — 3 24 — 4 24 — 4 24 — 4
Motor hp 1/6 1/6 1/4 1/4 1/4
Outdoor Cfm 2600 2600 3980 3980 3950
Fan Rpm 845 845 840 830 825
Watts 200 200 350 340 370
Full load amps 1.1
Refrigerant — 22 charge furnished 7 lbs. 5 oz. (-1)
7 lbs. 7 oz. (CAN) 7 lbs. 14 oz. 8 lbs. 3 oz. 9 lbs. 6 oz. 12 lbs. 13 oz.
Liquid line (o.d. in.) connection (sweat) 3/8 3/8 3/8 3/8 3/8
Vapor line (o.d. in.) connection (sweat) 3/4 3/4 7/8 7/8 1-1/8
Line voltage data — 60hz 208/230v -1ph
Compressor rated load amps 16.3 16.2 18.6 24.4 30.8
Rec. max. fuse or circuit breaker size (amps) 35 35 40 50 60
*Minimum circuit ampacity 21.5 21.3 25.0 32.2 40.2
*Refer to National Electric Code manual to determine wire, fuse and disconnect size requirements.
NOTE – Extremes of operating range are plus 10% and minus 5% of line voltage.
I – UNIT INFORMATION
10HP units are available in 1, 1 -1/2, 2, 2 -1/2, 3, 3 -1/2, 4
and 5 ton capacities.
All major components (indoor blower/coil) must be
matched according to Lennox recommendations for
the compressor to be covered under warranty. Refer to
the Engineering Handbook for approved system
matchups. A misapplied system will cause erratic
operation and can result in early compressor failure.
II – UNIT COMPONENTS
Unit components are illustrated in figure 1.
10HP UNIT COMPONENTS
EXPANSION
VALVE
CONTROL BOX
REVERSING VALVE
SUCTION
MUFFLER 10HP12
ONLY
COMPRESSOR
10HP12 SHOWN
OUTDOOR
FAN/MOTOR
10HP 12, 18, 24, 30 and 36 10HP42, 48, and 60
ACCUMULATOR
10HP12 ONLY REVERSING VALVE ACCUMULATOR
COMPRESSOR
OUTDOOR
FAN/MOTOR
CONTROL BOX
EXPANSION
VALVE
FIGURE 1
FAN
SPIDER

Page 3
A – Control Box (Figure 2)
FIGURE 2
DUAL CAPACITOR
(C12)
START CAPACITOR
(C7)
POTENTIAL
RELAY (K31)
COMPRESSOR
CONTACTOR
(K1)
10HP UNIT CONTROL BOX
GROUNDING
LUG
DEFROST
RELAY (K4)
DEFROST
CONTROL
CMC1
LOW VOLTAGE
MAKEUP AREA
TIMED OFF
CONTROL (A4)
10HP60 ONLY
A low voltage make up area is provided for thermostat
field wiring. Field thermostat wiring is made to color
coded pigtail connections as illustrated in figure 3.
FIGURE3
THERMOSTAT WIRING IDENTIFICATION
BLACK
BEIGE
ORANGE
YELLOW
RED
FROM OUTDOOR UNIT
TO INDOOR UNIT/
THERMOSTAT
24V (POWER) INPUT
TO OUTDOOR UNIT
(COMPRESSOR)
(REVERSING VALVE)
(ELECTRIC HEAT)
(COMMON)
INPUT
INPUT
DEFROST OUTPUT
DANGER
Shock Hazard
All 10HP units use single-pole
contactors. One leg of compressor,
capacitor and outdoor fan are
connected to line voltage at all
times. Potential exists for electrical
shock resulting in injury or death.
Remove all power at disconnect
before servicing.
Can cause personal injury or death.
1 – Compressor Contactor K1
The compressor is energized by a contactor located in
the control box. See figure 2. Contactors are SPST in
single phase units and 3PST in three phase units. K1 is
energized by the indoor thermostat terminal Y (24V).
10HP units are not equipped with a line voltage to 24V
transformer. All 24 VAC controls are powered by the
indoor unit. Refer to unit wiring diagram.
2 – Dual Capacitor C12
The compressor and fan in 10HP units use permanent
split capacitor motors. The capacitor is located inside the
unit control box (see figure 2). A single “dual” capacitor
(C12) is used for both the fan motor and the compressor
(see unit wiring diagram). The fan side and the
compressor side of the capacitor have different MFD
ratings. See table 1 for dual capacitor ratings.
TABLE 1
Unit MFD VAC
10HP (C12) DUAL CAPACITOR RATING
10HP18, 24 and
30-2
10HP42
10HP48 and 60
5
35
5
45
10
370
10
40
60
Terminal
FAN
HERM
FAN
HERM
FAN
HERM
FAN
HERM
440
10HP12 5
25
FAN
HERM
10HP30-1 and 36
10HP36-4 FAN
HERM 5 40
3 – Potential Relay K31 (Start)
All 10HP units use a potential relay which controls the
operation of the starting circuit. The potential relay is
located inside the unit control box (see figure 2). The
relay is normally closed when contactor K2 is
de-energized. When K1 energizes, the compressor
immediately begins start-up. K31 remains closed
during compressor start-up and start capacitor C7
remains in the circuit. As the compressor gains speed,
K31 is energized. When K31 energizes, the contacts
open and start capacitor C7 is taken out of the circuit.
4 – Start Capacitor C7
All 10HP units use a start capacitor (C7). C7 is located
inside the unit control box (see figure 2). C7 is wired in
parallel with the compressor side of the dual
capacitor. See table 2 for start capacitor ratings.
TABLE 2
Unit MFD VAC
10HP START CAPACITOR RATING (C7)
10HP12, 18 and 24
10HP36-4
10HP42 and 48
88–108 250
189-227 330
10HP36 (CAN)
10HP30-1 and 36 88–108 330
25088–108
10HP30-2 145–175 330
10HP60 270-324 330
5 – Timed Off Control A4
A timed off control (A4) located in the control box is
used on 10HP60 units. See figure 2. The time delay is
electrically connected between thermostat terminal Y
and the compressor contactor. After cooling demand
has stopped, A4 begins counting for five minutes.
During the timing period, A4 disables the compressor
contactor. Thermostat demand will have no effect on
the unit.The unit cannot operate. After the delay, the
compressor contactor can be energized.

Page 4
DANGER
Do not attempt to repair this control. Unsafe
operation will result. If the control has failed,
replace the control.
6 – Defrost Relay K4
The defrost relay controls defrost. The relay is a 3PDT
relay powered 24 VAC from the thermostat. K4 is
enabled during both cooling and heating modes
(except emergency heat). It is only powered when the
defrost control is calling for defrost. When energized,
the reversing valve and indoor auxiliary heat are
energized. Simultaneously, the outdoor fan is
de-energized. K4 latches in for the duration of the
defrost period. Refer to unit wiring diagram and
operation sequence in the back of this manual.
7 – Defrost Control CMC1
The CMC1 defrost control (figure 4) is a solid state control
manufactured by Hamilton Standard. The control
provides automatic switching from normal heating
operation to defrost mode and back. The control
provides 14 minute defrost periods at 30, 60 or 90 minute
field changeable intervals. The control monitors
thermostat demand and “holds” the timer in place
between thermostat demand. A set of diagnostic pins are
also provided for troubleshooting the unit.
The control contains a solid state timer which switches
an external defrost relay through 1/4” male spades
mounted on the control’s circuit board. When the
defrost thermostat closes (call for defrost), the defrost
timer initiates a 30, 60 or 90 minute (depending on how
the control is preset) timing sequence. If the defrost
thermostat remains closed when the timing sequence
ends, the defrost relay is energized and defrost begins.
SOLID STATE DEFROST CONTROL CMC1
Timing
Jumper
Timing Pins TroubleshootingPins Control Terminals
30 60 90
FIGURE 4
Defrost Control Components
1– Timing Pins 30, 60, 90
Each of these pins provides a different timed
interval between defrosts. A jumper connects the
pins to circuit board pin W1. Table 3 shows the
timings of each pin. The defrost interval can be field
changed to 30, 60 or 90 minutes. The defrost period
(14 minutes) cannot be changed. To change the
interval between defrosts, simply remove the
jumper from the pin it is connected to and
reconnect the jumper to one of the other available
pins (see figure 5).
TABLE 3
INTERVAL BETWEEN DEFROSTS
WITH JUMPER CONNECTED TO:
30 60 90
NORMAL
OPERATION
“TST” PINS
JUMPER
30 + 3 60 + 6 90 + 9 14 + 1.4
7 + 0.7 14 + 1.4 21 + 2.1 3.3 + 0.3
MIN. MIN. MIN. MIN.
SEC. SEC. SEC. SEC.
TOGETHER
CMC1 DEFROST
CONTROL
TIMINGS
DEFROST
TIME
1– Turn off all power to the unit to avoid circuit board damage.
2– Grasp wire connector firmly with fingers.
3–
Gently pull connector from pin.
4– Select new timing pin. DO NOT SELECT A “TST” PIN.
5– Gently push connector onto desired pin (see Table 3 for timings).
6– Turn on power to unit.
FIGURE 5
WARNING – AVOID CONTACT WITH OTHER CON-
TROL TERMINALS OR CONTROL COMPONENTS.
WARNING – DO NOT CONNECT
TIMING JUMPER TO EITHER
“TST” PIN.
TO CHANGE CONTROL TIMINGS:
DEFROST CONTROL TIMING CHANGES
2– Timing Jumper
The timing jumper is a factory installed jumper
on the circuit board used to connect pin W1 to
one of the three timing pins. The jumper may be
connected to any one of the timing pins but must
never be connected to either of the “TST” pins.
See Caution below.
CAUTION
        
          
       
  
3– “COM” Terminal
Terminal “COM” provides 24VAC Common.
4– “HLD” Terminal
Terminal “HLD” holds the internal timer in place
between thermostat demands and allows the unit to
continue timing upon resumption of thermostat
demand. Terminal “HLD” is connected directly to
thermostat demand.
NOTE – Hold function operates between thermostat
demands only when defrost thermostat is closed. This
is the only time that the timer is operating.

Page 5
5– “24V” Terminal
Terminal “24V” receives 24VAC from the control
transformer through the defrost thermostat. This
terminal powers the control’s internal timer and
relays. Terminal “24V” is powered only when there
is a call for defrost (defrost thermostat closed). The
timer begins timing at 0 only after terminal “24V”
receives power.
6– “OUT” Terminal
Terminal “OUT” controls defrost when connected
to one side of the defrost relay coil. An internal
relay connected to terminal “OUT” closes to allow
external defrost relay to energize and initiate
defrost. At the end of the defrost period, the
internal relay connected to terminal “OUT” opens
to de-energize the external defrost relay.
7– “TST” Pins
Each board is equipped with a set of test pins for
use in troubleshooting the unit. When jumpered
together, these pins reduce the control timing to
about 1/256 original time (see table 3 and figure 6).
IMPORTANT
Control will begin test mode only if normal load is
applied to control terminals. Do not attempt to
operate or test control out of unit.
A defrost period can last up to 14 minutes and can be
terminated two ways. If the defrost thermostat does
not open within 14 minutes after defrost begins, the
timer will de–energize the defrost relay and the unit
will resume normal operation. If the defrost
thermostat opens during the 14 minute defrost period,
the defrost relay is de–energized and the unit resumes
normal operation. Refer to figure 7.
FIGURE 6
WARNING – AVOID CONTACT WITH OTHER CONTROL
TERMINALS OR CONTROL COMPONENTS.
TO PLACE CONTROL IN TEST MODE:
1– Turn off all power to avoid damaging the circuit board.
2– Make sure all control terminals are connected as shown on
unit wiring diagram before attempting to place control in
test mode. See NOTE below.
NOTE – Control will not go into test mode when discon-
nected from unit. Unit load must be applied to control termi-
nals before the control will go into test mode.
3– Connect jumper to “TST” pins as shown.
4– Turn indoor thermostat to heat mode and adjust to highest
temperature setting.
5– Turn on power to unit.
6– See Table 3 for control timings in “TST” mode.
7– Be sure to turn off power and remove jumper when test is
complete. Turn on power and re–adjust thermostat.
DEFROST CONTROL TEST MODE
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
ÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉ
ÉÉÉ
ÉÉÉ
ÉÉÉ
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉÉÉÉÉ
ÉÉ
ÉÉ
ÉÉ
ÉÉ
CLOSED, ON
OPEN, OFF
THERMOSTAT DEMAND
DEFROST THERMOSTAT
DEFROST RELAY
DEFROST THERMOSTAT
DEFROST RELAY
THERMOSTAT DEMAND
DEFROST THERMOSTAT
DEFROST RELAY
THERMOSTAT DEMAND
DEFROST THERMOSTAT
DEFROST RELAY
10HP SERIES UNITS TYPICAL DEFROST TIMINGS
NORMAL HEATING OPERATION: DEFROST TERMINATED BY DEFROST THERMOSTAT
NORMAL HEATING OPERATION: DEFROST TERMINATED BY TIME
NORMAL HEATING OPERATION INTERRUPTED BY THERMOSTAT DEMAND: “HOLD” FUNCTION
DEFROST PERIOD INTERRUPTED BY THERMOSTAT DEMAND: “HOLD” FUNCTION
30/60/90 MINUTES
“HOLD” TIME
“HOLD” TIME
14 MIN. PLUS “HOLD” TIME
30/60/90 MINUTES
DEFROST THERMOSTATOPEN WITHIN 14 MINUTES
30/60/90 MINUTES 14 MIN. 30/60/90 MINUTES
30/60/90 MINUTES PLUS “HOLD” TIME
Note – Control begins timing at 0 when defrost thermostat closes. Defrost is terminated when defrost
relay is de–energized. Anytime defrost thermostat opens, defrost relay is immediately de–energized,
defrost timer resets and “HOLD” function stops.
DEFROST THERMOSTAT
MUST REMAIN CLOSED
FOR TIMER TO REMAIN
IN “HOLD”
DEFROST THERMOSTAT
MUST REMAIN CLOSED
FOR TIMER TO REMAIN
IN “HOLD”
FIGURE 7
ÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉÉ
THERMOSTAT DEMAND