Unit installation
Controls
SCXF-SVX01K-EN 69
Generic Building Automation System
Module Option
Generic building automation system module (GBAS)
provides broad control capabilities for building
automation systems other thanTrane’sTracer™ system. A
field provided potentiometer or a 0-5 vdc signal can be
applied to any inputs of GBAS to provide 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 a VA 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 parameters 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 44, p. 70. Reference Table 45, p. 70 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
Table 43. Minimum outside air setpoint w/VCM module
and Traq™ sensing
Unit Input volts Cfm
SXWF 20 0.5 - 4.5 vdc 6,325-8,500
SXWF 22 0.5 - 4.5 vdc 6,325-9,350
SXWF 25 0.5 - 4.5 vdc 6,500-10,625
SXWF 29 0.5 - 4.5 vdc 8,700-12,325
SXWF 32 0.5 - 4.5 vdc 8,700-13,600
SXWF 35 0.5 - 4.5 vdc 9,100-14,875
SXWF 38 0.5 - 4.5 vdc 9,880-16,150
SXWF 42 0.5 - 4.5 vdc 11,200-17,859
SXWF 46 0.5 - 4.5 vdc 11,960-19,550
SXWF 52 0.5 - 4.5 vdc 14,250-22,100
SXWF 58 0.5 - 4.5 vdc 15,080-24,650
SXWF 65 0.5 - 4.5 vdc 16,900-27,625
SXWF 72 0.5 - 4.5 vdc 18,700-29,800
SXWF 80 0.5 - 4.5 vdc 20,800-29,800
SXRF 20 0.5 - 4.5 vdc 6,500-10,625
SXRF 25 0.5 - 4.5 vdc 8,700-12,325
SXRF 29 0.5 - 4.5 vdc 8,700-13,600
SXRF 30 0.5 - 4.5 vdc 9,100-14,875
SXRF 35 0.5 - 4.5 vdc 9,880-16,150
SXRF 40 0.5 - 4.5 vdc 11,960-19,550
SXRF 50 0.5 - 4.5 vdc 15,080-24,650
SXRF 60 0.5 - 4.5 vdc 20,800-29,800