Trane IntelliPak SCWG 020 - Manual (Page 82)

82 SCXG-SVX01B-EN
Generic Building Automation
System Module Option
The generic building automation system
module (GBAS) provides broad control
capabilities for building automation
systems other than Trane’s Tracer
®
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 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 discontinues, the
unit’s cooling/heating functions become
fully enabled again.
GBAS 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 input.
Owner
General
Information
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 in Table O-GI-6 on page 83.
Reference Table O-GI-7 on age 83 for
corresponding input voltage setpoints.
Following are formulas to calculate input
voltage or setpoint. SP = setpoint, IPV =
input voltage.
If the setpoint range is between 50-90 F:
IPV = (SP - 50) (0.1) + 0.5
SP = [(IPV - 0.5)/0.1] + 50
If the setpoint range is between 40-90 F:
IPV = (SP - 40)(0.8) + 0.5
SP = [(IPV - 0.5)/0.08] + 40
If the setpoint range is between 40-180
F:
IPV = (SP - 40)(0.029) + 0.5
SP = [(IPV - 0.5)/0.029] + 40
If the static pressure range is between
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 between
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 disables when
the demand limit binary input closes. The
heating demand limit definition 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%, 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
using 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 2 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.