Remote Minimum Position Potentiometer (5U70) (BAYSTAT023A)
The remote minimum position potentiometer is used on units with an economizer. It allows the operator to remotely set the economizer's minimum position (which controls the amount of outside air entering the unit). Use the installation instructions that shipped with the potentiometer to install it, and the appropriate illustrations in Figure
External Auto/Stop Switch (5S67)
A field supplied single pole single throw switch (5S67) may be used to shut down the unit operation. This switch is a bi- nary input wired to the RTM. When opened, the unit shuts down immediately and can be cancelled by closing the switch. Refer to the appropriate illustrations in
Figure
VOM Contacts (5K90, 5K91, 5K92, 5K93, 5K94)
If the unit is equipped with a Ventilation Override Module (VOM), (i.e. unit model number digit 21+ is a “N”), a num- ber of special functions can be specified by the building owner or contractor. These functions can include, but are not limited to; (1) Unit Off, (2) Pressurization, (3) Exhaust,
(4)Purge, and (5) Purge with Duct Pressure Control. They are controlled by binary inputs wired to the VOM. These functions can be initiated by; a toggle switch, a time clock, or an ICSTM output. The switch must be rated for 12 ma @ 24 VDC minimum. The following preset sequences can be modified by the customer;
1.VOM Mode “A” Priority 1 - Unit Off:
2.VOM Mode “B” Priority 2 - Pressurize:
3.VOM Mode “C” Priority 3 - Exhaust:
Installation (Continued)
4.VOM Mode “D” Priority 4 - Purge:
5.VOM Mode “E” Priority 5 - Purge with duct pressure control:
S/A Pressure Control with supply air pressure high limit disabled.
"OFF" - will appear in the Ventilation Override screen after all VOM binary inputs have been reset (opened).
Due to codes in some areas, the definitions for some or all of the VOM modes may have to be locked into the program by the user. Once the definitions are locked, the Ventilation Override Module must be replaced in order to reprogram that sequence.
Refer to Figure
Emergency Override Definitions (with
When an
PRESSURIZE
Supply Fan - On
Inlet Vanes - Open (if equipped) Exhaust Fan - Off (if equipped)
Exhaust Dampers - Closed (if equipped) OA Dampers - Open
Heat - All heat stages Off (staged gas and elec.), Hydronic heat & Mod Gas Heat output at 0%. Occupied/Unoccupied output - Energized
VO Relay - Energized (with VOM module installed) OA Preheater State - Off (with VCM module installed)
DEPRESSURIZE
Supply Fan - Off
Inlet Vanes - Closed (if equipped) Exhaust Fan - On (if equipped) Exhaust Dampers
Heat - All heat stages Off (staged gas and elec.), Hydronic heat & Mod Gas Heat output at 0%. Occupied/Unoccupied output -
VO Relay - Energized (with VOM module installed) OA Preheater State - Off (with VCM module installed)
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