FHP CA CONSOLE series Installation Instructions Manual - page 5
970-293 Revised 05-12
UNIT PROTECTION MODULE (UPM)
The Unit Protection Module (UPM) as shown in figure 1, is
a printed circuit board (PCB) that interfaces with the
thermostat or the digital direct controller.
The main purpose of this device is to protect the
compressors by monitoring the different states of switches
and sensors of each refrigerant circuit, this device provides
time delays and protects the unit against freezing of the
water and refrigerant heat exchangers as well as condensate
overflow when the appropriate sensors are installed.
Figure1
t
Figure 1
Alarm output is Normally Open (NO) dry contact. If 24 VAC
output is needed R must be wired to the ALR-COM
terminal; 24VAC will be available on the ALR-OUT terminal
when the unit is in alarm condition. If pulse is selected the
alarm output will be pulsed.
POWER RANDOM START UP
This feature prevents multiple units sharing same
electrical circuit or network from starting at the same
time.
It assures that Heat Pumps sharing the same electrical
circuit
do
not
demand
high
inrush
currents
simultaneously when starting back up after a power
failure.
If the controller has been completely powered down for
more than 28 milliseconds, a random delay is initiated
typically the unit will start between the time range of 270
and 300 seconds, this only if the controller is set to
normal operation (test switch set to NO).
In order for the random sequence to initiate the unit
power must be removed completely.
IMPORTANT
: If the board is set to “TEST” mode through
the “TEST” DIP switch SW1 delay will be 10 seconds.
ANTI SHORT CYCLE DELAY
This feature protects the compressor short cycling if the Y
call is set and removed.
The anti short cycle delay is 300sec delay on break during
normal operation.
NOTE
: If the board is set to test mode through the “TEST”
DIP switch the delay will be 5 seconds.
Y CALL
The UPM will energize the compressor’s output (CC) in an event
of a “Y” call from a thermostat or controller (after the random
start up and/or the anti short cycle delays have elapsed). Y
input terminal must be energized with a 24 VAC signal.
HIGH AND LOW PRESSURE PROTECTION
The UPM monitors the state of the High and Low pressure
Switch inputs of each refrigerant circuit, HPC and LPC on the
board respectively, these switches must be closed in order
for the controller to energize the compressor output (CC).
The CC output will only be energized when the switches are
closed and the
anti short cycle
(and /or random start up
when applicable) has expired.
HIGH PRESSURE PROTECTION
If the HPC switch is open upon a Y call the UPM will not
energize the CC output and therefore the compressor will
remain off, the fault LED will flash one (1) time for the HPC
and the alarm contact will remain off.
If the compressor is running in normal mode on a Y call
and the high pressure switch opens, the UPM will shut
down the compressor output and will keep it off until the
switch closes and the anti short cycle has expired. The
controller will keep track of the number of times the
switch opens, if within one (1) hour period the switch
opens the number of times set via the DIP switch the
controller will shut the compressor down and perform a
hard lockout condition under this condition the alarm
contact will be energized.
The UPM allows the user to configure the counts that the
HPC will be allowed to open within one hour before the
UPM performs a hard lockout on the compressor. The user
can select either two or four times by changing switch
four (4) on the DIP switch SW1 (shown on table 3) on the
UPM board.
LOW PRESSURE PROTECTION
If the LPC switch is open upon a Y call the UPM will not
energize the CC output and therefore the compressor will
remain off, the fault LED will flash two (2) times for the LPC
and the alarm contact will remain off.
If the compressor is running in normal mode on a Y call and
the low pressure switch opens, the UPM will keep the
compressor running for two (2) minutes if the condition
remains after this period of time the compressor will shut
down and the UPM will start a soft lockout. The UPM will flash
two (2) times for the LPC. And the alarm contact will remain off.
5
CA CONSOLE SERIES