Bryant PREFERRED 581J - Manual (Page 56)

56
SEQUENCE OF OPERATION (cont.)
On the initial power to the EconoMi$er IV control, it will
take the damper up to 2 1/2 minutes before it begins to
position itself. After the initial power--up, further changes
in damper position can take up to 30 seconds to initiate.
Damper movement from full closed to full open (or vice
versa) will take between 1 1/2 and 2 1/2 minutes. If free
cooling can be used as determined from the appropriate
changeover command (switch, dry bulb, enthalpy curve,
differential dry bulb, or differential enthalpy), then the
control will modulate the dampers open to maintain the
mixed--air temperature setpoint at 50_F (10_C) to 55_F
(13_C). If there is a further demand for cooling (cooling
second stage -- Y2 is energized), then the control will
bring on compressor stage 1 to maintain the mixed--air
temperature setpoint. The EconoMi$er IV damper will be
open at maximum position. EconoMi$er IV operation is
limited to a single compressor.
Heating
The sequence of operation for the heating is the same as
an electromechanical unit with no economizer. The only
difference is how the economizer acts. The economizer
will stay at the Economizer Minimum Position while the
evaporator fan is operating. The outdoor--air damper is
closed when the indoor fan is not operating.
581J