Troubleshooting guide

MAGNUM VERSION 8 MANUAL REVISION 3.1
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When the discharge control pressure is greater than 250 psi the relay VFD ENABLE will be on and the VFD
on the fan will be set to 100%. If the discharge control pressure drops to 210, then the fan speed will be set to
60%. The discharge control pressure is half of its Cut In and Cut Out range (250 – 170 = 80 / 2 = 40= 170 =
210) therefore, the VFD will be positioned to half of its range (100 –20 = 80 / 2 = 40 + 20 = 60). The VFD will
continue to be modulated in this matter until the discharge control pressure drops below 170. Then the VFD
will be at 0% and relay VFD ENABLE will remain on. If the pressure goes above 170 the VFD will be
modulated. For example if the discharge control pressure goes to 190.0 the VFD will be set to 50%.
Fan control when a fault occurs:
If a fault occurs, an alarm message will be generated, relay VFD LOAD will Lock off, relay VFD ENABLE will
be off, the VFD speed will be set to 0% and the bypass, VFD BYPASS, will be enabled if needed after waiting
for 30 seconds, Setpoint #90. Once the fan bypass is enabled and the discharge control pressure goes above
250 psi the bypass will be turned on enabling the fan to run at 100% and it will remain on regardless of the
discharge control pressure.
If the fault resets itself, and is no longer on, the state of VFD LOAD will be set to AUTO, the VFD BYPASS
relay will be turned off and VFD will be enabled to control the fan speed if it is needed.
7.75. Boiler/Pump Control
Boiler/Pump control logic has been added to the standard HVAC software. This will provide similar but limited pump
control that is provided in Loop Water Control (LWC) software. This will enable boilers and their associated pumps to
be controlled without the need to add an additional MCS Magnum with LWC software to control these functions.
MCS-Config Requirements 7.75.1.
The following panel has been added to the Magnum HVAC V8 Information screen as the setup for the
Boiler/Pump information.
7.75.1.1. Enable Boiler Logic?
If No is selected the additional Boiler Information will not appear. The Boiler logic is inactive.
If Yes is selected the additional Boiler Information will appear and the Boiler logic is active.
7.75.1.2. General
Select the Run/Stop Switch and the Alarm Relay from dropdown lists (if applicable).
Select either Water In or Water Out for the control of the boilers.
Select the Water In and Water Out sensors from dropdown lists (if applicable).
7.75.1.3. Pumps
Select the Pump Control method: