Reznor RCB User Manual

Form CP-MAPSIII-D21, Doc No 303070, Page 10
3.0 Controls
(Cont’d)
3.4 Heating Control
3.4.1 Electric Heat Staging
A call for heat will occur when the discharge air temperature is 5°F(2.8°C) below
the active setpoint. When the OAT is below 65°F/18°C (Heating Lockout SP), the
unit enables the electric heat to maintain the active setpoint. The unit will stage as
shown in the staging chart and the PI loop will activate. Stages should be assumed
cumulative from the previous stage.
Electric Heat Staging
PI Loop Control: All Statements Must Be True To Activate or De-Activate.
All stages will have an adjustable min ON and OFF time.
Stage Outputs
Increase
Inter-Stg
Timer
Activate
Decrease
Inter-Stg
Timer
De-activate
Stg 1 NO8 = ON
DAT 5°F (2.8°C) below setpoint
(Y3 Modulates via Heating Demand)
15 min
Heating Demand < 2.5% & DAT 5°F
(2.8°C) above setpoint
Stg 2 NO9 = ON 10 min
Heating Demand > 70% & DAT
5°F(2.8°C) below setpoint
2 min
Heating Demand < 5% & DAT
5°F(2.8°C) above setpoint
Stg 3 NO10 = ON 10 min
Heating Demand > 75% & DAT
5°F(2.8°C) below setpoint
2 min
Heating Demand < 10% & DAT
5°F(2.8°C) above setpoint
Stg 4 NO11 = ON 10 min
Heating Demand > 80% & DAT
5°F(2.8°C) below setpoint
2 min
Heating Demand < 20% & DAT
5°F(2.8°C) above setpoint
Stg 5 NO12 = ON 10 min
Heating Demand > 85% & DAT
5°F(2.8°C) below setpoint
2 min
Heating Demand < 30% & DAT
5°F(2.8°C) above setpoint
Stg 6 NO13 = ON 10 min
Heating Demand > 90% & DAT
5°F(2.8°C) below setpoint
2 min
Heating Demand < 40% & DAT
5°F(2.8°C) above setpoint
All parameters are factory level access.
3.4.2 Gas Heat Staging
A call for heat will occur when the discharge air temperature is 5°F(2.8°C) below
the active setpoint. When the OAT is below 65°F/18°C (Heating Lockout SP), the
unit enables the gas heat to maintain the active setpoint. The unit will stage and
modulate as shown in the staging chart and the PI loop will activate. Stages should
be assumed cumulative from the previous stage.
Gas Heat Staging
PI Loop Control: All Statements Must Be True To Activate or De-Activate.
All stages will have an adjustable min ON and OFF time.
Stage Outputs
Increase
Inter-Stg
Timer
Activate
Decrease
Inter-Stg
Timer
De-activate
Stg 1
Y3 = 24% for
30 seconds
& NO8 = ON
DAT 5°F (2.8°C) below setpoint
(Y3 Modulates Heat Exchanger 1
via Heating Demand)
15 min
Heating Demand < 2.5% & DAT
5°F (2.8°C) above setpoint
Stg 2
Y4 = 24% for
30 seconds
NO9 = ON
10 min
Heating Demand > 50% (Y3
Heat Exhanger 1 = 100%) & DAT
5°F(2.8°C) below setpoint (Y4
Modulates Heat Exchanger 2 via
Heating Demand)
15 min
Heating Demand < 25% & DAT
5°F(2.8°C) above setpoint
All parameters are factory level access.
When the unit has a call for cooling from the th-tune device (Option CL78) in the
space, it will use the unit U4 DAT input and the cooling demand to achieve the space
cooling discharge air temperature setpoint. A call for space cooling takes priority over
acallforspacedehumidication.
A call for mechanical cooling will occur when the discharge air temperature is
5°F(2.8°C) above the active setpoint. When the OAT is above 65°F/18°C (Cooling
Lockout SP), the unit enables the mechanical cooling to maintain the active setpoint.
Cooling capacity/staging will follow a PI loop to maintain the active setpoint. Space
CoolingActive=SpacedehumidicationY5Reheat_Mod_CapacityandNO17Reheat
Compressor Command not permitted.
3.5.1 Cooling Staging
Control Y3 (with the
Option CL78 th-tune
device ENABLED and
COMMUNICATING)
3.5 Cooling Control
Heat Exchanger 1 Heat Exchanger 2
0%
100%
Output Y3
Heating Demand
100%
10 Vdc
Output Y4
0%
2 Vdc
100%
10 Vdc
0%
2 Vdc
50%

Reznor RCB Specifications

General

Brand	Reznor
Model	RCB
Category	Air Handlers
Language	English