550.38-N1Y
Unitary Products Group
13
®
SYSTEM CONTROLLER - HDB076 ONLY
Controls operation as follows:
1.
RANDOM START - Upon initial application of power and
a 2.5 second time delay, the compressor contactor will
be energized.
2.
ANTI-SHORT CYCLE - Once the unit is energized, a
momentary interruption of power, i.e., thermostat cycling,
greater than 8 milliseconds, will initiate the compressor
lockout time delay of five minutes regardless of the con-
dition of the inputs. Upon completion of the 5 minute
lockout delay the system will automatically reset allowing
the compressor contactor to energize.
3.
SAFETY SWITCH - Upon interruption of power to the
compressor via the high pressure or low pressure switch,
the compressor contactor will be locked out indefinitely.
Reset will occur when the pressure switch recloses and
power has been removed and reapplied via the system
circuit breaker or by cycling the thermostat temperature
setting from maximum cool to maximum heat and back
to desired cool setting. During lockout the fault indicating
lamp shall be on.
4.
LOW PRESSURE SWITCH BY-PASS TIME DELAY -
The low pressure switch is by-passed for a period of 75 -
105 seconds to allow the system to start and stablize.
After the delay period has expired the system will then
be maintained by the low pressure switch. In the event
that the low pressure switch should open after the delay
period while the compressor is running the system will
go into lockout. Note depending upon how the system is
wired the lockout may automatically be reset or may
require a manual reset.
System Time Delays are as follows: Random Start = 2.5 sec-
onds; Lockout = 5 minutes; Low Pressure By-pass = 75 - 105
seconds.
INSTRUCTING THE OWNER
Assist owner with processing warranty cards. Review Owners
Guide and provide a copy for the owner guidance on proper
operation and maintenance. Instruct the owner or the opera-
tor how to start, stop and adjust temperature setting.
When applicable, instruct the owner that the compressor is
equipped with a crankcase heater to prevent the migration of
refrigerant to the compressor during the “OFF” cycle. The
heater is energized only when the unit is not running. If the
main switch is disconnected for long periods of shut down, do
not attempt to start the unit until 8 hours after the switch has
been connected. This will allow sufficient time for all liquid
refrigerant to be driven out of the compressor.
The installer should also instruct the owner on proper opera-
tion and maintenance of all other system components.
INDICATIONS OF PROPER OPERATION
Cooling operation is the same as any conventional air condi-
tioning unit.
The following checks may be made to determine if the sys-
tem is operating properly:
1.
The outdoor fan should be running, with warm air being
discharged from the top of the unit.
2.
The indoor blower (furnace or air handler) will be operat-
ing, discharging cool air from the ducts.
3.
The vapor line at the outdoor unit will feel cool to the
touch.
4.
The liquid line at the outdoor unit will feel warm to the
touch.
If unit is not operating properly, check the following items
before calling a serviceman:
1.
Indoor section for dirty filter.
2.
Outdoor section for leaf or debris blockage.
Eliminate problem, turn off the thermostat for 10 seconds and
attempt start. Wait 5 minutes. If system does not start, call
service technician.
MAINTENANCE
1.
Dirt should not be allowed to accumulate on the outdoor
coils or other parts in the air circuit. Clean as often as
necessary to keep the unit clean. Use a brush, vacuum
cleaner attachment, or other suitable means.
2.
The outdoor fan motor is permanently lubricated and
does not require periodic oiling.
3.
If the coil needs to be cleaned, it should be washed with
Calgon CalClean (mix one part CalClean to seven parts
water). Allow solution to remain on coil for 30 minutes
before rinsing with clean water. Solution should not be
permitted to come in contact with painted panel surfaces.
4.
Refer to the furnace or air handler instructions for filter
and blower motor maintenance.
5.
The evaporator coil drain pan should be inspected and
cleaned regularly to prevent odors and assure proper
drainage.
WHEN THE SYSTEM IS FUNCTIONING PROPERLY AND
THE OWNER HAS BEEN FULLY INSTRUCTED, SECURE
THE OWNER'S APPROVAL.
