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There is also a 5-minute compressor time delay
function built into the HPC. This is to protect the
compressor from short cycling conditions. The board's
LED will have a fast blink rate when in the compressor
time delay. In some instances, it is helpful to the
service technician to override or speed up this timing
period and shorting out the SPEEDUP terminals for a
few seconds can do this.
Low Pressure Switch Bypass Operation
The control has a selectable (SW1) low pressure switch
bypass set up to ignore the low pressure switch input
during the first (30, 60, 120 or 180 seconds) of "Y"
operation.
After this period expires, the control will then monitor
the low pressure switch input normally to make sure
that the switch is closed during "Y" operation.
High Pressure Switch Operation
The control has a built-in lockout system that allows
the unit to have the high pressure switch trip up to two
times in 1 hour and only encounter a "soft" lockout.
A "soft" lockout shuts the compressor off and waits
for the pressure switch to reset, which at that point
then allows the compressor to be restarted as long
as the 5-minute short cycle timer has run out. If the
high pressure switch trips a third time within 1 hour,
the unit is in "hard" lockout indicating something is
certainly wrong and it will not restart itself.
Vent Connection Plug
All units are equipped with a vent connection plug in
the side of the control panel for the different ventilation
packages to plug in to. If the compressor will not start
and there is no "Y1" at the defrost board, first check to
make sure that either the optional vent is plugged into
the vent connection plug or the supplied jumper plug
is in place. The unit will not operate without anything
plugged in. This plug is located on the side of the
control panel behind the front vent door (behind the
filter access door). If the unit is supplied with a factory-
installed vent package, it will be plugged in but the
jumper plug will also be tethered next to the connection
for troubleshooting purposes, if necessary.
Pressure Service Ports
High and low pressure service ports are installed on
all units so that the system operating pressures can be
observed. Pressure tables covering all models can be
found beginning on page 37. It is imperative to match
the correct pressure table to the unit by model number.
This unit employs high-flow Coremax valves instead of
the typical Schrader type valves.
WARNING! Do NOT use a Schrader valve core removal
tool with these valves. Use of such a tool could result in
eye injuries or refrigerant burns!
Manual 2100-790
Page
30 of 49
To change a Coremax valve without first removing the
refrigerant, a special tool is required which can be
obtained at www.fastestinc.com/en/SCCA07H. See the
replacement parts manual for replacement core part
numbers.
Service Hints
1. Caution owner/operator to maintain clean air
filters at all times and to not needlessly close off
supply and return air registers. This reduces airflow
through the system, which shortens equipment
service life as well as increasing operating costs.
2. Check all power fuses or circuit breakers to be sure
they are the correct rating.
3. Periodic cleaning of the outdoor coil to permit full
and unrestricted airflow circulation is essential
.
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Table of Contents
Troubleshooting
