Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
57
Example: Fluid Cooler with condenser compressor fans 7.40.6.
The economizer AO has been selected and there are no separate economizer fans.
The condenser type is RO Step Individual and the Fluid Cooler Economizer option has been enabled. The
individual compressor condenser fans will be controlled by the economizer function unless a compressor is
running. If a compressor is running, then the condenser fans associated with that compressor will be
controlled based upon the discharge pressure of the compressor that is running.
Assume the following setup:
Conditions when the run/stop was set to RUN
Ambient temperature 30.0F
Control temperature 49.7
The ambient temperature is less than 44.0 (Setpoint #1) – 10.0 (Setpoint #119) and no mechanical cooling
steps are on, therefore the Unit state will be ECONOMIZER ONLY and the economizer function will be
enabled.
The AO M-1 “ECONOMIZER” will be opened to its minimum valve of 10% (Setpoint #121) and it will be
modulated based upon the control temperature and the target (Setpoint #1). The first adjustment will be
49.7 – 44.0 = 5.7. This value will be adjusted by multiplier of 2 (Setpoint #126) and divided by 1 (Setpoint
#127) to give an adjusted value of 11.4. This value is blocked by the maximum allowed adjustment
Setpoint # Name Value
1 SPPY TRGT 44.0F
2 CTRL ZONE+ 2.0F
3 CTRL ZONE- 1.0F
27 MAX ROC- -.6F
28 MAX ROC+ .6F
107 ECON-MECHdly 240s
115 EconVFDdelay 45s
119 EcoOffsetON 10.0F
120 EconDelyFans 60s
121 EcoVlvMinVlv 10.0%
122 EcoVlvMaxVlv 100.0%
123 EcoVlvMaxAdj 10.0%
124 EcoVlvDelay 30s
125 EcoVlvMaxDly 120s
126 EcoVlv Mul 2
127 EcoVlv Div 1
Analog
output
Name
AO M-1 ECONOMIZER