High pressure protection
If the HP1 or HP2 switches are open upon a
Y1 or Y2 call the UPM will not energize the
respective CC1 or CC2 outputs and
therefore the correspondent compressor will
remain off, the fault LED will flash one (1)
time for the HP1 and 3 times for HP2 and
the alarm contact will remain off.
If a compressor is running in normal mode
on a Y call (Could be Y1 or Y2 or both) 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 HP 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 LP1 or LP2 switches are open upon a
Y1 or Y2 call (Could be Y1 or Y2 or both)
the UPM will not energize the CC1 or CC2
outputs and therefore the correspondent
compressor will remain off, the fault LED will
flash two (2) times for the LP1 and 4 times
for the LP2 and the alarm contact will remain
off.
If the compressor is running in normal mode
on a Y call (Could be Y1 or Y2 or both) 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 LP1, four
(4) times for the LP2 and the alarm contact
will remain off.
If the switches close, the UPM will start the
compressor after the anti short cycle has
expired UPM will energize the compressor
output.
IMPORTANT:
To exit the hard lockout the controller must be reset
from the Y or R terminal by removing the power from
the selected terminal. The user can choose which will
be the reset point via the DIP switch SW1.
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