Page 4
1 – Compressor Contactor K1
The compressor is energized by a contactor located in
the control box. See figures 3 and 4. Contactors are
SPST in single phase units and 3PST in three phase
units. K1 is energized by the indoor thermostat
terminal Y (24V). HP23 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.
DANGER
Shock Hazard
All single phase HP23 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.
2 – Dual Capacitor C12
The compressor and fan in single phase units use
permanent split capacitor motors. The capacitor is
located inside the unit control box (see figure 3). 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
HP23 (C12) DUAL CAPACITOR RATING
HP23–211/261
HP23–311-1/411
HP23–461
HP23–511/651
5
35
5
45
10
370
10
40
60
Terminal
FAN
HERM
FAN
HERM
FAN
HERM
FAN
HERM
440
HP23–141
5
25
FAN
HERM
HP23–311-2
5
35
FAN
HERM
HP23–411-2
5
40
FAN
HERM
3 – Potential Relay K31 (Start)
All single phase 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 3). 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 single phase units use a start capacitor (C7). C7 is
located inside the unit control box (see figure 3). 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
HP23 START CAPACITOR RATING (C7)
HP23–141/211/261
HP23–411–2/461/511
88–108
250
189-227
330
HP23–411 (CAN)
HP23–311-1/411
88–108
330
250
88–108
HP23–651
270-324
330
HP23–311-2
145–175
330
5 – Timed Off Control A4 (–651 / –653 only)
A time delay (A4) located in the control box is used on
the HP23-650-2 series. See figures 3 and 4. 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.
DANGER
Do not attempt to repair this control. Unsafe
operation will result. If the control has failed,
replace the control.
6 – Fan Capacitor C1
The fan in three-phase units uses a single phase
permanent split capacitor motor. A single capacitor C1 is
used for the fan motor. C1 is located inside the unit
control box (see figure 4). Table 3 shows the ratings of C1.
TABLE 3
Unit
MFD
VAC
HP23 FAN CAPACITOR RATING (C1)
HP23–413Y,G
HP23–463/513/653G
HP23-513,653J
7.5
370
5
370
HP23-463/513/653Y
10
370
7 – Transformer T5
Transformer T5 is used on all “J” voltage units. T5 is
used as a step-down transformer for fan B4. T5 is rated at
3.4 VA with a 575 volt primary and a 460 volt secondary.
8 – 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.
