Trane SCXG-SVX01B-EN manual Generic BuildingAutomation System Module Option

general

Operation information

Generic BuildingAutomation System Module Option

The generic building automation system module (GBAS) provides broad control capabilities for building automation systems other than Trane’sTracer system. A field provided potentiometer or a 0-5 vdc signal can be applied to any of the inputs of the GBAS to provide the following points:

GBAS Analog Inputs

Four analog inputs that can be configured to be any of the following:

(1)occupied zone cooling

(2)unoccupied zone cooling

(3)occupied zone heating

(4)unoccupied zone heating

(5)SA cooling setpoint

(6)SA heating setpoint

(7)space static pressure setpoint

(8)SA static pressure setpoint

GBAS Binary Outputs

Five binary outputs to provide diagnostics, signaling up to five alarms. Each of the five (5) relay outputs can be mapped to any/all of the available diagnostics. Each output contains a dry N.O. and N.C. contact with aVA rating of 2 amps at 24 VAC.

GBAS Binary Input

One binary input for the self-contained unit to utilize the demand limit function. This function is operational on units with a GBAS and is used to reduce electrical consumption at peak load times. Demand limiting can be set at either 50% or

100%. When demand limiting is needed, mechanical cooling and heating (with field-provided 2-stage electric heat only) operation are either partially (50%), or completely disabled (100%) to save energy.The demand limit definition is user definable at the HI panel. Demand limit binary input accepts a field supplied switch or contact closure. When the need for demand limiting has been discontinued, the unit’s cooling/heating functions will again become fully enabled.

GBAS Communication (Analog Inputs) The GBAS accepts external setpoints in the form of analog inputs for cooling, heating, supply air pressure. Refer to the unit wiring diagram for GBAS input wiring and the various desired setpoints with the corresponding DC voltage inputs.

Any of the setpoint or output control parameters can be assigned to each of the four analog inputs on the GBAS module. Also, any combination of the setpoint and/or output control param- eters can be assigned to the analog inputs through the HI.To assign the setpoints apply an external 0-5 vdc signal:

1.directly to the signal input terminals, or

2.to the 5 vdc source at the GBAS module with a 3-wire potentiometer.

Note: There is a regulated 5 vdc output on the GBAS module that can be used with a potentiometer as a voltage divider. The recommended potentiometer value is 1000- 100,000 ohms.

The setpoints are linear between the values shown inTable O-GI-6 on page 66. ReferenceTable O-GI-7 on page 66 for corresponding input voltage setpoints. Following are formulas to calculate input voltage or setpoint. SP = setpoint, IPV = input voltage.

If the setpoint range is 50-90°F: IPV = (SP - 50) (0.1) + 0.5

SP = [(IPV - 0.5)/0.1] + 50

If the setpoint range is 40-90°F: IPV = (SP - 40)(0.8) + 0.5

SP = [(IPV - 0.5)/0.08] + 40

If the setpoint range is 40-180°F: IPV = (SP - 40)(0.029) + 0.5

SP = [(IPV - 0.5)/0.029] + 40

If the static pressure range is 0.03-0.3 iwc:

IPV = (SP - 0.03)(14.8) + 0.5

SP = [(IPV - 0.5)/14.8] + 0.03

If the static pressure range is 0.0-5.0 iwc: IPV = (SP)(0.8) + 0.5

SP = [IPV/(0.8 + 0.5)]

GBAS Demand Limit Relay (Binary Input) The GBAS allows the unit to utilize the demand limit function by using a normally open (N.O.) switch to limit the electrical power usage during peak periods. Demand limit can initiate by a toggle switch closure, a time clock, or an ICS control output. These contacts must be rated for 12 ma @ 24 VDC minimum.

When the GBAS module receives a binary input signal indicating demand limiting is required, a command initiates to either partially (50%) or fully (100%)

inhibit compressor and heater operation. This can be set at the HI using the setup menu, under the “demand limit definition cooling” and “demand limit definition heating” screens. A toggle switch, time clock, or building automation system control output can initiate demand limiting.

If the cooling demand limit is set to 50%, half of the cooling capacity will disable when the demand limit binary input closes. The heating demand limit defini- tion can only be set at 100%, unless the unit has field-provided two-stage electric heat. In that case, if the heating demand limit is set to 50%, half or one stage of heating disables when the demand limit binary input closes. If the demand limit definition is set to 100%, then all cooling and/or heating will disable when the demand limit input closes.

GBAS Diagnostics (Binary Outputs) The GBAS can signal up to five alarm diagnostics, which are fully mappable through the setup menu on the HI. These diagnostics, along with the alarm output on the RTM, allow up to six fully mappable alarm outputs.

Each binary output has a NO and NC contact with a rating of two amps at 24 VAC.The five binary outputs are factory preset as shown on the unit wiring diagram (on the unit control panel door). However, these outputs can be field defined in a variety of configurations, assigning single or multiple diagnostics to any output.

For a complete listing of possible diagnos- tics, see the IntelliPak Self-Contained Programming Guide, PKG-SVP01B-EN. For terminal strip locations, refer to the unit wiring diagram for the GBAS.

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