Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
82
7.74.3.9. Modulating
7.74.3.9.1. Modulating Common
This type of condenser uses water for condenser cooling. The AO Modulating Valve will modulate the cold water valve
based upon the system’s highest discharge pressure.
48 CND ADJ DELAY
(Modulating Type)
If active this is the time in seconds between condenser
adjustments to the AO. If inactive, then 30 seconds will be
used as the delay.
If type is DELAY: (required for condenser relay delays).
-MIN VFD Opening cell contains the time delay between
turning on a relay and moving the AO to its minimum position
(Setpoint #52).
-MAX VFD Opening cell contains the time delay between turning
off a relay and moving the AO to 100%.
49 CND START %
(Modulating Type)
If active, then the value is the starting % for the AO when the RO that
is tied to it turns on. The value in the “Time (SEC)” cell is the AO
starting stage. If no Relays are used when CMP starts set value.
50 CND TARG
(Modulating Type)
Target the logic will try to maintain by modulating the AO.
51 CND ADJ DIV
(Modulating Type)
Controls scaling of the amount the AO is adjusted (usually 1). The
larger the number the smaller the AO adjustment as the
adjustment will be divided by this value.
52 CND MIN %
(Modulating Type)
Minimum AO % allowed.
If compressor is off, then check the “Time (SEC)” field:
If 0, then the AO % will be set to the value of this Setpoint. If 2 and the
run/stop is set to run, then set the AO % to 100%, else set the AO
% to 0%. This option is selected in the “Default Valve Opening %
when Comp. is OFF” box in the condenser information section in
the MAG HVAC screen.
53 CND ROC-
(Modulating Type)
Maximum negative rate of change allowed. If the rate of change is
less than this Setpoint, then stop modulating the AO. The absolute
value of this Setpoint also serves as the maximum positive rate of
change allowed. If the rate of change is greater than the absolute
value of this Setpoint, then stop modulating the AO.
54 CND ADJ MULT
(Modulating Type)
Controls scaling of the amount the AO is adjusted. The larger the
number the larger the AO adjustment as the adjustment will be
multiplied by this value.
55 CND MIN ADJ
(Modulating Type)
The value in this Setpoint is the minimum % the AO will be modulated
when a change is made.
90 COND FAULT For Condensers with Fault Indicators: If Setpoint is active, a condenser
fault occurs, and the Setpoint type is Alarm, then an alarm
message will be generated. If the type is Lockout, and a condenser
fault occurs, then all of the compressors associated with this fault
will be locked off.