Robertshaw SlimZone CLASSIC ZONE CONTROL SYSTEM - Manual (Page 11)

5. SYSTEM OPERATION
5.1 INITIAL POWER UP
When first powered up, the control panel will immediately process any fan calls from the
zone thermostats but will ignore any heating or cooling calls for a maximum delay of 4
minutes. After the 4 minute minimum off delay has been satisfied, the control panel will
then accept heating or cooling calls from the zone thermostats.
5.2 ESTABLISHING MODE OF OPERATION
The equipment mode of operation (HEAT, COOL, AUTO) is determined according to the
signals present at the C and H terminals at the Zone #1 input on the control panel (Figure
4.2). The C and H input signals take precedence on any other signals from the zone
thermostats. The mode is established according to the following sequence:
Input signal
present on: Mode of Operation Functionality
C COOL ONLY Only cool calls answered; heat calls ignored
H HEAT ONLY Only heat calls answered; cool calls ignored
no signals AUTO All calls answered; panel is in *First Call Priority mode
Table 5.1: Mode of operation
* In the First Call Priority mode, first call for heating or cooling will establish the mode of
equipment operation.
5.3 SEQUENCE OF OPERATION
Once the heating or cooling mode is established and a call for that mode has been
received by the panel, the control panel will energize the proper damper relays to allow the
conditioned air into the calling zone(s). The panel will close any zone dampers not
matching the established mode of operation. Fan call inputs will be ignored by the panel.
The control panel will keep the equipment operating in the established mode for a minimum
on time of 4 minutes and until all zones calling for the established mode of operation are
satisfied. Once all zones are satisfied, the control panel will de-energize the equipment and
will initiate a minimum off timer of 4 minutes to prevent equipment short cycling. The
control panel will continue to operate the fan for a period of 45 seconds to purge
conditioned air into the last zone(s) calling. After the purge cycle, the panel will perform
the following: 1) if no zone thermostats are calling for constant fan, all zone dampers will
be opened and the fan relay de-energized to allow for any hard wired low speed fan
distribution of air into all zones; 2) if any zone is calling for constant fan, the control panel
will keep the fan relay energized and open all zone dampers.
When the SlimZone Classic control panel is in the AUTO mode of operation (no input
signals on C and H Zone #1 terminals), it operates on a first call priority. As described
above, the control panel searches the zone thermostats looking for heating or cooling calls.
When a mode of operation has been established, the panel will operate in that mode. If
during this time an opposite call is received, the panel will continue with the established
mode of operation until the initial call(s) has been satisfied, the purge cycle has been
completed and the 4 minute delay timer will be initiated. If after the 4 minute delay, the
control panel is receiving a call for the opposite mode, it will change mode of operation to
satisfy the new calls as described above.
SlimZone Classic 9