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RLC-SVX09Q-EN
In general, when there is either a non-latching or latching
diagnostic, the EWP relay is turned off as though there was
a zero time delay. Exceptions (see Table 60) whereby the
relay continues to be energized occur with:
A Low Chilled Water Temp. diagnostic (non-latching)
(unless also accompanied by an Evap Leaving Water
Temperature Sensor Diagnostic)
OR
A starter contactor interrupt failure diagnostic, in which a
compressor continues to draw current even after
commanded to have shutdown
OR
A Loss of Evaporator Water Flow diagnostic (non-latching)
and the unit is in the AUTO mode, after initially having
proven evaporator water flow.
Alarm and Status Relay Outputs
(Programmable Relays)
A programmable relay concept provides for enunciation of
certain events or states of the chiller, selected from a list of
likely needs, while only using four physical output relays, as
shown in the field wiring diagram. The four relays are
provided (generally with a Quad Relay Output LLID) as part
of the Alarm Relay Output Option. The relay’s contacts are
isolated Form C (SPDT), suitable for use with 120 Vac
circuits drawing up to 2.8 amps inductive, 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 18. Alarm and status relay output configuration
Alarm
Description
Latching Alarm
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.
Non-latching Alarm
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 Circuit 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 Circuit 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.
Chiller Limit Mode
This output is true whenever a circuit on the chiller 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.
Warning
The output is true whenever there is any active warning diagnostic that is associated with the Unit, Circuit, or any of the
compressors on a circuit.
Max 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.
See the Max Capacity Relay specification for more information.
Evaporator 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.
Service Request
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.
Ice Making Status This output is true when Ice Building status is active.
Condenser Freeze Avoidance Request
The Condenser Freeze Avoidance Request Relay will indicate when the condenser water pump is being commanded
on in an override mode – this relay can provide therefore, the means of wiring additional pump, bypass valves, or to
defeat the Condenser Pump Override, so as to still provide the necessary heat flow into the condenser to avoid a
freeze.
Alarm – General Latching Unit
This output is true whenever there is latching alarm(s) that targets chiller or all circuits or all the compressors on a
circuit so that the unit is unable to produce any capacity. It means that it activates when there is latching alarm on
Chiller or ‘General Latching Circuit X’ on every circuits.
Installation - Electrical
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