Robertshaw DSL-520P, Installation And Operation Manual

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5.6 SEQUENCE OF OPERATION
5.6.1 TIMESHARE MODE
Note: The following assumes the control module is in the auto mode of operation.
A. Control module receives zone requests for heating and cooling. First mode to satisfy the
number of zones requirement for first stage is serviced.
B. Equipment is activated:
- W1 is energized for heating and Y1 is energized for cooling (in both heat/cool and heat pump
mode).
- B terminal is energized for heating and O terminal is energized for cooling.
- Both G1 & G2 fan terminals are energized.
- Dampers to zones calling for that mode are open.
- 20 minute timer is initiated.
C. Equipment stays ON for at least minimum ON time.
D. In the heat pump mode, if the 20 minute timer runs out and the opposite mode is being
requested, the control module will changeover to the opposite mode (timesharing) by toggling
the reversing valve output terminals (O and B). The compressor is not turned OFF.
E. When the equipment call is satisfied (in both heat/cool and heat pump mode), or when the 20
minute timer has elapsed and the opposite mode is being requested (in heat/cool mode), the
equipment is turned OFF and a 45 second purge cycle begins:
- W1 or Y1 is deenergized.
- G2 is deenergized; G1 remains energized.
- B or O terminal remains energized.
- Zone dampers remain open.
F. After the 45 second fan purge, the equipment will remain OFF for at least the duration of the
minimum OFF time for the equipment which was just serviced. The control module will remain
in one of the following conditions during this period:
- If global constant fan selected, all zone dampers open and G1 remains ON to circulate air.
- If only local constant fan is requested, dampers to zones requesting constant fan open and
all other dampers close. G1 remains ON.
- If constant fan not requested and no other equipment calls are present, G1 is deenergized and
dampers to last zones calling remain open.
- If constant fan is not requested and calls for the opposite mode of equipment are received by
the module, G1 is deenergized and dampers to the zones calling for the opposite mode are
open and all other dampers are closed.
G. After the minimum OFF time, the control module will service the opposite mode of equipment
if calls for it are pending; steps A to E are repeated. If there are no pending calls for the
opposite mode, the control module is ready to service any calls.
NOTES:
•
When changing over to the opposite mode of equipment, the control module will start with
the first stage of equipment even if enough zones are calling to activate additional stages.
The module will upstage every five (5) minutes afterwards; auxiliary heat stage in the heat
pump mode will energize fifteen (15) minutes after the last compressor stage.
SlimZone Premier 17