AC-SVX002C-EN
39
7.2 amps resistive, or 1/3 HP and for 240 VAC circuits
drawing up to 0.5 amp resistive.
The list of events/states that can be assigned to the
programmable relays can be found in the following
table. The relay will be energized when the event/state
occurs.
Table 17.
Alarm and status relay output
configurations
Description
Alarm
(Latching)
This output is true whenever there is any
active latching shutdown diagnostic that
targets the Unit, Circuit, or any of the
Compressors on a circuit.
Alarm
(Non-Latching)
This output is true whenever there is any
active non-latching shutdown diagnostic that
targets the Unit, Circuit, or any of the
Compressors on a circuit.
Alarm
This output is true whenever there is any
active latching or non-latching shutdown
diagnostic that targets the Unit, Circuit, or
any of the Compressors on a circuit.
Alarm Ckt 1
This output is true whenever there is any
active latching or non-latching shutdown
diagnostic that targets Circuit 1, or any of the
Compressors on Circuit 1.
Alarm Ckt 2
This output is true whenever there is any
active latching or non-latching shutdown
diagnostic that targets Circuit 2, or any of the
Compressors on Circuit 2.
Unit Limit Mode
This output is true whenever a circuit on the
unit has been running in one of the limit
modes continuously for the Limit Relay
debounce time. A given limit or overlapping of
different limits must be in effect continuously
for the debounce time prior to the output
becoming true. It will become false if no limits
are present for the debounce time.
Compressor
Running
The output is true whenever any compressor
is running.
Circuit 1
Running
The output is true whenever any compressor
of Circuit 1 is running.
Circuit 2
Running
The output is true whenever any compressor
of Circuit 2 is running.
Ice Making
This output is true when Ice Building status is
active.
Maximum
Capacity
The output is true whenever the unit has
reached maximum capacity continuously for
the Max Capacity Relay debounce time. The
output is false when the unit is not at
maximum capacity continuously for the filter
debounce time.
Table 17.
Alarm and status relay output
configurations (continued)
Description
Evaporator
Water Freeze
Avoidance
Request
This relay output is energized any time either
the Low Evaporator Water Temperature – Unit
Off or the Low Evaporator Temperature Ckt x
– Unit Off diagnostics are active. This relay is
intended for use as an external interlock for a
field engineered and provided solution to
mitigate the freeze danger implied by these
diagnostics. Generally, this would be used in
cases where operation of the evaporator
water pump is unacceptable due to the
system constraints, (i.e. such as mixing
unconditioned warm water with controlled
supply water as provided by other parallel
chillers. The relay’s output can provide the
method to close bypass valves so the
circulation becomes local to the evap and
excludes the load, or can be used to defeat
the evap pump override entirely while
initiating an independent source of heat / flow
to the evap.
None
This selection is desirable to provide an easy
way for a customer to defeat the effect of the
relay, if it has already been wired. For
instance, if the relay was normally
programmed as an "alarm" relay, and was
wired to a claxon, it may be desirable to
temporarily defeat the feature without
changing wiring.
Service
Request
(for unit
compressor or
water pump)
This relay will be energized when at least one
Maintenance alert condition (refer to Service
required message specification) occurs, as
long as at least one of associated
informational diagnostic(s) will be active.
Hot Water
Control
The output is true if capacity control is in Hot
Water Control mode (water temperature
being controlled to the Active Hot Water
Setpoint). The output is false in any other
capacity control mode (Chilled Water Control,
Ice Making, etc.)
Relay Assignments Using Tracer
TU
Tracer
®
TU Service Tool is used to install the
Programmable Relay Option package and assign any of
the above list of events or status to each of the four
relays provided with the option. (See Tracer
®
TU
section of Controls chapter for more information on
this service tool.) The relays to be programmed are
referred to by the relay’s terminal numbers on the LLID
board 1A18.
The default assignments for the four available relays of
the Programmable Relay option are show in the table
below.
