13
ACB (Auxiliary Control Board) Interface — The
ACB interface is a dry contact board that can output up to four
signal  controlling  devices.  Refer  to  Fig.  15  and  24  for
connecting devices to the ACB interface board
Fig. 24 —ACB Interface
START-UP
Pre-Start Check — 
Once installation is complete, make
the following pre-start checks:
1. All indoor and outdoor units are properly installed.
2. All piping and insulation is complete.
3. All  electrical  connections  (both power  and  control)  are
properly terminated.
4. All condensate drains are installed correctly.
5. The power supply is the right voltage and frequency. 
6. The  units  are  properly  grounded  in  accordance  with
current electrical codes.
7. Suction  and  liquid  line  service  valves  are  in  the  open
position.
System Operation Check — Once  the  installation
and pre-start checks are complete, perform the following steps:
1. Using  the  remote  controller,  select  cooling  or  heating
mode to check the operation of the system.
2. While the system is in operation, check the following on
the indoor unit:
a. Switches  or  buttons  on  the  remote  controller  are
easy to push.
b. Indicator light is showing normal operation and no
error is indicated.
c. Swing  mode  of  air  louvers  is  working  (if
applicable to unit).
d. Drain pump operation is normal (if applicable).
e. No abnormal vibration or noise.
3. While the system is in operation, check the following on
the outdoor unit:
a. No abnormal vibration or noise is noticed.
b. Condenser fan is in operation.
c. Indicator light is showing normal operation and no
error is indicated.
NOTE: If the unit is turned off or restarted, there is a time delay
of three minutes for the compressor to start from the time the
power is restored.
MAINTENANCE
EVERY 3 MONTHS:
• Check  the  air  filter  condition.  Clean  or  replace  if
necessary.
EVERY 6 MONTHS:
Follow the 3-month maintenance schedule. In addition:
• Clean condensate tray with suitable cleaning agent.
• Clean the grille and panel, if applicable.
EVERY 12 MONTHS:
Follow the 6-month maintenance schedule. In addition:
• Be sure all electrical connections are secure.
• Check condensate pump operation.
• Check the heating and cooling action to confirm proper
operation.
INDOOR UNIT ADDRESSING
For  proper  system  operation,  each  indoor  unit  must  have  a
unique address set from 0 to 63. When setting an address by
remote  controller,  the  outdoor  units,  indoor  units,  and  MDC
must be powered on. If FE is displayed on the LED screen or
display board, this unit has no address. After setting all indoor
unit addresses, turn off the power supply to all indoor units to
clear the errors.
Indoor unit addressing can be distributed automatically in the
heat pump system. When dip switch “S6” on the outdoor unit’s
main  PCB  board  is  set  to  00  (default set  in  factory),  indoor
units  are  set  for  auto-addressing.  When  powering  on for the
first time, it takes six minutes or more to finish auto-addressing
each indoor unit. The heat recovery system cannot accomplish
this function at this time.
IMPORTANT: The system  can  connect  64 indoor  units,
with different system addresses. If two indoor units in the
same system have identical addresses, abnormal operation
will occur.
LEGEND
ACB
—
Auxiliary Control Board
FAN
—
Output for fan Operation
CTON
—
Output for Cooling Operation
HTON
—
Output for Heating Operation
AUXH
—
Output for Auxiliary Heat
MAX AMPS 1A
MAX VOLTAGE 24V
ACB interface 
FAN
CTON
HTON
AUXH
CAUTION
When  servicing  or  repairing  this  unit,  use  only  factory-
approved  service  replacement  parts.  Refer  to  the  rating
plate  on  the  unit  for  complete  unit  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 and may result in equipment damage.
CAUTION
To avoid equipment damage, do not attempt to reuse any
mechanical  or  electrical  controllers  that  have  been  wet.
Replace defective controller.