Instruction manual

72 McQuay OM 920
Operator’s Guide
Determining Occupancy Mode
Occ Mode is an adjustable item which sets the unit for manual occupied, unoccupied, tenant
override or automatic operation. The parameter is adjustable via the following path: Standard
Menu/Occupancy/Occ Mode.
Occ
When Occ Mode is set to “Occ,” the unit is manually placed in the occupied mode of
operation.
Unocc
When Occ Mode is set to “Unocc,” the unit is manually placed in the unoccupied mode of
operation.
TntOvrd
When Occ Mode is set to “TntOvrd,” the unit is manually placed in the tenant override mode
of operation.
Note – Once tenant override operation is activated the parameter automatically reverts back to
“Auto.”
Auto
When Occ Mode is set to “Auto” the automatically changes between occupied, unoccupied
and tenant override operation.
Determining Occupancy Source
When the Occupancy parameter indicates Occ, the Occupied Source is set to one of the
following values to indicate the function responsible for placing the unit into the occupied
mode of operation. The current Occupancy Source can be viewed via the following path:
Standard Menu/Occupancy/OccSrc.
None The Occ Src= parameter indicates “None” when the Occupancy= parameter indicates
“Unocc” or “Tnt Ovrd.”
NetSchedule The Occ Src= parameter indicates “Net Schd” when the Occupancy= parameter
indicates “Occ” due to a network schedule indicating an occupied period.
IntSchedule The Occ Src= parameter indicates “Int Sched” when the Occupancy= parameter
indicates “Occ” due to the unit internal Schedule.
OneEventSchedule The Occ Src= parameter indicates “Int Sched” when the Occupancy=
parameter indicates “Occ” due to the unit one event Schedule.
RemoteSwitch The Occ Src= parameter indicates “Remote Sw” when the Occupancy=
parameter indicates “Occ” due to a field supplied external time clock or a tenant override
switch signal in the form of a set of dry contacts is closed across terminals 101 and102 on the
unit field terminal block TB2.
OccManCmd The Occ Src= parameter indicates “OccManCmd” when OccMode is set to
Auto and the network manual occupancy command is set to Occupied.
OccMode The Occ Src= parameter indicates “Occ Mode” when the Occupancy= parameter
indicates “Occ” due to the Occupancy Mode being manually set to “Occ.”
TStatTO The Occ Src = parameter indicates “TStatTO” when the Occupancy= parameter
indicates “Occ” due to the tenant override button on the zone thermostat is pushed. The button
must be held for at least 1 second but not more than 30 seconds.
ManTO The Occ Src = parameter indicates “ManTO” when the Occupancy= parameter
indicates “Occ” due to the being manually set via the keypad/display. When the Tenant
Override Timer is set to a non-zero value, the unit starts and runs in the tenant override mode
regardless of any scheduling features. The unit stops when the timer expires. The Tenant
Override Timer can be set from 0-300 minutes.