Manual 2100-537
I
Page 39 of 54
HIGH PRESSURE SWITCH
(TERMINALS HP1 & HP2) Circuit will be proved as
“closed” prior to energizing “A” or “CC” terminals. If
pressure switch opens, compressor will go into soft lockout
mode and compressor operation will be terminated; green
fault light illuminated. Logic control will then go through
5-minute delay on break + random start sequence. If no
fault found on next run cycle, compressor will continue
operation. If fault reoccurs, hard lockout occurs, and fault
signal is sent to “L” terminal.
LOW PRESSURE SWITCH
(TERMINALS LP1 & LP2) Circuit will be proved as
“closed” prior to energizing “A” or “CC” terminals. The
conditions of the LP terminals will then be ignored for the
rst 90 seconds after a demand for compressor operation.
Following this 90 second period, if pressure switch opens,
compressor will go into soft lockout mode and compressor
operation will be terminated; orange fault light illuminated.
The control board will then go through a 5-minute delay
on break + random start sequence. If no fault found on
next run cycle, compressor will continue operation. If fault
reoccurs, hard lockout occurs, and fault signal is sent to “L”
terminal.
FREEZE STAT (Optional Field Add-On
Option)
(TERMINALS FS & FS2) Circuit will be proved as
“closed” prior to energizing “A” or “CC” terminals. If
freezestat switch opens, compressor will go into soft lockout
mode and compressor operation will be terminated; red
fault light illuminated. Logic control will then go through
5-minute delay on break + random start sequence. If no
fault found on next run cycle, compressor will continue
operation. If fault reoccurs, hard lockout occurs, and fault
signal is sent to “L” terminal.
NOTE: Jumper wire is factory installed.
CONDENSATE OVERFLOW
(Terminals CO & CO
2
) This input operates when the water
level in the condensation pan rises and completes a signal
across the terminals of the terminal block located in the
indoor coil drain pan; yellow fault light illuminates. If fault
clears, the logic control will go through 5-minute delay +
random start. If fault reoccurs, or didn’t clear the rst time
after 30 seconds, the control will go into hard lockout, and
will energize the “L” output signal.
SEQUENCE OF OPERATION
UNDER & OVER VOLTAGE PROTECTION
When an under or over voltage condition exists, the
controller locks out the unit. When condition clears,
the controller automatically releases the unit to normal
operation and the compressor restarts after the random start
and anti-short cycle timings are met. The under & over
voltage protection starts at plus or minus 20% from nominal
voltage and returns to operation at plus or minus 10% from
nominal voltage. All four (4) LED fault lights will ash
when an under or over voltage condition occurs. The over
voltage protection can be disabled by removing the O/V
jumper.
INTELLIGENT RESET
The Geothermal Logic Control has an intelligent reset
feature after a safety control is activated. The controller
locks out the unit for 5 minutes, at the end of this period, the
controller checks to verify that all faults have been cleared.
If faults have been cleared, the controller restarts the unit.
If a second fault occurs, the controller will lock out the unit
until the unit is manually reset by breaking “Y” signal from
thermostat. The last fault will be kept in memory after a full
lockout; this is only cleared by cycling the power.
ALARM OUTPUT
The “L” terminal has 24 volts applied when a hard lockout
occurs. This can be used to drive a fault light or a low
voltage relay.
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 can be found later in the manual covering all
models. It is imperative to match the correct pressure table
to the unit by model number.
SYSTEM START-UP
Step 1 – Close disconnect switch(es) and set the thermostat
to cool and the temperature to the highest setting.
Step 2 – Check for proper airow across the indoor coil.
Step 3 – Connect the service gauges and allow the unit to
run for at least 10 minutes or until pressures are
stable. Check pressures to the system pressure
table attached to the unit service panel.
Step 4 – Fill out Ground Source Heat Pump Performance
Report.
