Orion System HB Controller - Manual (Page 4)

Sequence of Operations
HB Controller Technical Guide 4
Fan Mode
The HB Controller supports 2 different Supply Fan confi gurations. It
can be confi gured for Adjustable Two-Speed Fan or Two-Speed Fan. On
a call for “G,” the Supply Fan runs at Low Speed. Minimum on and off
times are maintained in the event of a short cycled call for “G.”
Heating Mode
On a call for “W1,” the Supply Fan runs at High Speed (maintained
during the Heating mode), and Heat Stage 1 is energized. On a call for
“W2,” Heat Stage 2 is energized after the Stage-Up delay. If “W2” is
called without “W1,” Heat Stage 1 is energized, and then Heat Stage 2
is energized after the Auto Stage-Up Delay period. On a call for “W3,”
Heat Stage 3 is energized after the Stage-Up delay. If “W3” is called
without “W1” or “W2,” Heat Stages 1, 2, and 3 will energize based on
Auto Stage-Up Delays.
Cooling Mode
If the HB Controller is confi gured for 1 stage of Cooling, on a call for
“Y1,” the Supply Fan runs at High speed, and Cool Stage 1 will energize.
If the HB Controller is confi gured for 2 stages of Cooling, on a call for
“Y1,” the Supply Fan runs at Low Speed, and Cool Stage 1 is energized.
On a call for “Y2,” the Supply Fan runs at High Speed, and Cool Stage
2 is energized after the Stage-Up Delay. If “Y2” is called without “Y1,”
Cool Stage 1 is energized, and then Cool Stage 2 is energized after the
Auto Stage-Up Delay.
Economizer Cooling
General Economizer Operation
If the Outdoor Air Temperature is below the Economizer Enable Setpoint
and there is a call on “Y1,” the compressors will be locked out, and the
Economizer will modulate to achieve a 55° F Supply Air Temperature.
If the HB Controller is confi gured for 1 stage of Cooling, on a call for
“Y1,” the Supply Fan will run at High Speed. If the HB Controller is
confi gured for 2 stages of Cooling, on a call for “Y1,” the Supply Fan
will run at low speed. When “Y2” is called, the Supply Fan will go to
high speed.
Economizer Operation with ECS Control
If the Enthalpy Changeover Switch (ECS) is closed and the outdoor air
temperature is below the ECS, OAT Enable setpoint (default 65° F),
the economizer will modulate and attempt to achieve 55° F supply air
temperature. If the outdoor air temperature is above 55° F, the econo-
mizer will generally open to 100%. Mechanical cooling can be used
to supplement the economizer if the outdoor air temperature is above
the ECS OAT Enable setpoint and the economizer signal is at 100%.
Once mechanical cooling is activated to supplement the economizer, the
economizer will remain at 100% until the cooling call is satisfi ed.
Mechanical Cooling Staging with ECS Control
If the HB Controller is confi gured for 1 stage of Cooling, on a call for
“Y1,” the Supply Fan will run at High Speed. Cool Stage 1 will activate
after the Cooling Auto Stage-Up Delay. If the HB Controller is con-
fi gured for 2 stages of Cooling, on a call for “Y1,” the Supply Fan will
run at Low Speed. Cool Stage 1 will activate after either the Cooling
Auto Stage-Up Delay Expires or a call for “Y2” is made. When “Y2”
is called, Cool Stage 2 will activate after the Cooling Auto Stage-Up
Delay. After Cool Stage 2 is activated, the Supply Fan will switch to
High-Speed operation.
Economizer IAQ Control
The economizer is also used for CO
2
control. If the CO
2
level is above
the Minimum CO
2
PPM setpoint, the Economizer Minimum Position will
be reset proportionally between the Minimum CO
2
PPM and Maximum
CO
2
PPM setpoints. When the CO
2
level is above the Maximum CO
2
PPM setpoint, the Economizer will open as far as the Maximum Damper
Adjustment Position setpoint setting. There are two Minimum and two
Maximum Economizer Damper Positions depending on the Supply Fan
speed. These are the Maximum Damper Position with Low-Speed Fan,
the Minimum Damper Position with Low-Speed Fan, the Maximum
Damper Position with High-Speed Fan, and the Minimum Damper Posi-
tion with High-Speed Fan. The air balancing contractor should determine
these settings in order to maintain the proper amount of fresh air being
supplied to the building.
Economizer Dehumidifi cation
1-or 2-Stage Cooling Units with Adjustable
Two-Speed or Two-Speed Supply Fan Control
If the Outdoor Air Temperature is below the Economizer Enable Setpoint
and there is a call for Dehumidifi cation on “RH,” the compressors will
be locked out, and the Economizer will modulate to achieve 55° F Sup-
ply Air Temperature. The Supply Fan will run at Low Speed, and the
Return Air Bypass will be closed.
For 1 stage Cooling units, on a call for “Y1,” the HB Controller will
enter the Cooling Mode, and the Supply Fan will run at High Speed. The
Cooling Mode will be maintained until “Y1” is satisfi ed. As long as there
is still a call for “RH,” the Dehumidifi cation Mode will resume.
For 2 stage Cooling Units, “Y1” is ignored during this mode to extend
Dehumidifi cation. On a call for “Y2,” the HB Controller will enter the
Cooling mode, and the Supply Fan will run at High Speed. The Cooling
Mode will be maintained until both “Y2” and “Y1” are satisfi ed. As long
as there is still a call for “RH,” the Dehumidifi cation Mode will resume,
and the Supply Fan will run at Low Speed.
If the HB Controller is confi gured for 1 stage of Heating, on a call for
“W1,” the mode changes to Heating. The Economizer will close to its
Minimum Position, Heat Stage 1 will energize, and the Supply Fan will
run at High Speed.
If the HB Controller is confi gured for 2 or 3 stages of Heating, on a call
for “W1,” the Economizer will be locked at its current position, attempt-
ing to deliver 55° F Supply Air to the heating section. Heat Stage 1 is
energized, and the Supply Fan will run on High speed. On a call for “W2,”
the HB Controller will enter the Heating Mode. The Economizer will
move to its Minimum Position, and Heat Stage 2 will energize after the
Stage-Up Delay. The Heating Mode will be maintained until both “W2”
and “W1” are satisfi ed. W3 is also available for 3 Stage Electric Heating
Units. As long as there is still a call for “RH,” the Dehumidifi cation Mode
will resume, and the Supply Fan will run at Low Speed.
Controller Sequence of Operations