Manual 2100-746D
Page
21 of 59
Lead/Lag Rotation
Pressing the Advance Lead button on the home
screen will cause the lead to advance to the next unit.
This may be useful during service and maintenance
procedures.
Lead unit will be determined by an internal timer and
Lead-Lag Changeover Time selected by user. The Lead-
Lag Changeover Time will be configurable with a range
of 1 to 30 days and can be disabled by setting duration
to 0 for an overall range of 0 to 30. Default setting
for Lead-Lag will be 7 days. Lead unit will rotate after
Lead-Lag Changeover Time expires. At expiration, the
lead unit will rotate to the next available unit (Example:
1 to 2) and once the last address used expires the
lead unit will restart at unit 1. Lead-Lag configuration
will apply to both heating and cooling. If disabled by
setting to 0, the lead unit will only rotate manually by
utilizing the Advance Lead button. Humidification and
dehumidification will not rotate lead. The lead unit will
always be unit 1. This will allow users to mix dehum
and non-dehum units in a single application. (Dehum
units will need to be placed in the lowest unit address
locations, i.e., unit 1 will always be the first dehum
unit when installed for use with the MC5300/5600.)
Number of units used for Lead-Lag will be determined
by user configurable setting in the Setup Menu.
When Lead-Lag Changeover Time expires and lead unit
is shifted, the call will be satisfied and then the lead
unit will rotate. If the Advance Lead button is used to
rotate the lead unit, the call will end, the lead unit will
be shifted and units will restage in accordance with the
demand.
Cooling Sequence of Operation
The controller will utilize Y1 and Y2 to control cooling
for each configured unit. If the units are configured for
single stage cooling, Y1 will be energized for cooling
and Y2 will not be used. If the units are configured
for 2 stage cooling, Y1 will be energized for the first
stage and Y2 will be energized for the second stage for
each configured unit. Each terminal energized per unit
will count as a single stage for cooling staging logic.
Cooling stages may be either economizer or mechanical
cooling depending upon the unit's configuration.
Heating Sequence of Operation
Electric Heat
The controller will use the W1 and W2 terminals
to control conventional heating operation for each
configured unit. If units are configured for single
stage electric heat then W1 will be energized at each
configured unit and W2 will not be used. If units
are configured for 2 stage electric heat then W1 will
be energized first and W2 will be energized for an
additional stage of electric heat at each configured
unit. Each terminal energized will count as a single
stage for staging logic. If units are configured for heat
pump operation in conjunction with electric heat, the
electric heat (W1 & W2) will be added as additional
stages of heat with preference given to heat pump
stages.
Heat Pumps
The controller will use terminals Y1, Y2 and O/B
to control heat pump operation for each configured
unit. If units are configured for single stage heat
pump operation, Y1 will be energized and O/B will
be energized (or de-energized depending upon
configuration) for heat pump operation. If units are
configured for two stage heat pump operation, Y1 will
be energized and O/B will be energized (or de- energize
depending upon configuration) first and Y1, Y2 and
O/B will be energized (or de-energized depending upon
configuration) for an additional stage of heat pump
operation. O/B configuration will determine if O/B will
energize or de-energize for heat pump operation and
will be included in the Guided Setup options.