Johnson Controls HMH72B36 User Manual

Activating pump down mode
The compressor runs with a target frequency and without
any protection when the frequency rises. The EEV runs
with an open setting. The outdoor unit fan runs with the
set fan speed.
1. Remove line voltage power from the outdoor
section.
2. Close the liquid line service valve using a hex head
wrench by turning the valve stem fully clockwise
until seated as shown in Figure 32.
Figure 32: Refrigerant collection
3. Open the maintenance panel.
4. Place the unit in pump-down mode by changing
the dip switch setting on the main control board as
shown in Figure 31.
5. Restore line voltage power to the outdoor section.
6. Note that the LED display on the main control board
should display 40. This number then counts down to
zero.
7. When the LED begins to blink zero, close the vapor
line service valve using a hex head wrench by
turning the valve stem fully clockwise until seated as
shown in Figure 32.
8. Remove line voltage power from the outdoor
section.
Note: Make sure to switch back the dip switch
setting after the refrigerant recovery operation. If
not, the unit enters the refrigerant recovery mode
again after powering on.
NOTICE
The refrigerant in systems with linesets in excess of
40 ft cannot be recovered into the outdoor unit and
requires recovery with external equipment.
Running a parameter query
Figure 33: 7-segment display query
Figure 34: HMH72B24/HMH72B36 digital display board
parameters
There are three buttons on the digital display board:
• Select: Press to display outdoor or indoor unit
parameter. P.= The parameter of the outdoor unit.
• Increase: Press to increase the number by one.
• Decrease: Press to decrease the number by one.
Note: The parameter content is automatically
displayed after the parameter code is selected for 3
s.
Table 6: Parameters - HMH72B24/HMH72B36
Parameter code Description
P.0 Fault codes
P.1
Compressor actual
frequency
P.2
Compressor driving
frequency
P.4
Compressor target
frequency
P.5
Compressor discharge
temperature
Installation Manual: HMH7 Series - 17 SEER Horizontal Discharge Modulating Heat Pump 29
Johnson Controls Ducted Systems

Johnson Controls HMH72B36 Specifications

General

Brand	Johnson Controls
Model	HMH72B36
Category	Heat Pump
Language	English