+12V
S
ALARM
NC COM NO
X
XX
ALARM RELAY
LOCATION ON
MASTER PCB
SECTION DETAIL MASTER PCB
ALARM RELAY DETAIL
The Nucleus Electrical Control Board has one Alarm Relay Circuit. See Master PCB location
above. The alarm relay is rated for the following:
30 Volts DC, 2A Max, 60W, NO Only, SELV, LPS or Class 2
The alarm relay is only activated based on input from the primary RTD temperature probe on
the mixed water outlet (T3). The alarm has a preset default
MIN (65°F)
and
MAX (130°F)
in
the commissioning menu, and it will activate on measured temperature values of T3 above
or below these
MIN / MAX
values. The above values are user adjustable and programmable
in the commissioning menu. See
COMMISSIONING
section in this manual, starting on page
13.
Once alarm has been triggered, the error must be manually cleared from the LCD screen by
pressing
ENTER.
If alarm condition is still present, the
TTML
(page 15) begins and alarm is re-
triggered after
TTML
has elapsed. This process can continue until outlet temperature is
within the
MIN / MAX
parameters. The alarm will be de-activated as soon as the measured
temperature value at T3 returns to a measured value between
MIN
and
MAX
.
When in a non-alarm state, the relay is in a
Normally Closed (NC)
position. When the alarm
is triggered, the relay switches to a
Normally Opened (NO)
position.
MASTER PCB DETAILS
The Primary PCB for this device comes with the following connectivity:
1.
Linear motor connection for valve motion.
2.
Four standard temperature input channels
–
T1, T2, T3, T4
–
all are 3-wire RTD
connection types.
3.
Two standard pressure input channels
–
P1 & P2
The Primary PCB also has the ability to receive a plug-in protocessor for standard industry
protocols (6 native on board) and communication to a Building Management System via
Ethernet or RS-485.
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