Lx – WH Series Installation and Operation Instructions
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Trinity Lx
57
Low Voltage Connections
The Trinity Lx low voltage junction box is located in the lower left corner of the water heater cabinet on
Lx200WH models and can be accessed by removing the front door of the water heater, followed by the removal
of the low voltage junction box cover. On Lx300WH & Lx400WH models, the low voltage junction box is
located at the top of the water heater cabinet on the left hand side and can be accessed by removing the top front
cover of the water heater. On Lx500WH-Lx800WH models, the low voltage junction box is located at the back
of the water heater cabinet and can be accessed by removing the top back cover of the water heater. Each water
heater is provided with one hole and two knockouts for routing field wiring into the low voltage junction box.
Low voltage field connections identified in Tables 12-2(a) and 12-2(b) are to be read in conjunction with Figure
12-2.
Table 12-2(a) Low Voltage Field Connections (Lx200WH-Lx400WH)
Connection
Location
Description
COM
(24VAC)
1
24VAC Common
– Neutral for the 24VAC power supply within the water heater.
R
(24VAC)
2
24VAC Hot
- Power supply for inputs LIM, CH1, and CH2 (LL).
3
LIM
4
External Limit
– Input requiring 24VAC from terminal R to permit the burner to
operate. Comes factory equipped with a jumper to the R terminal. Remove the factory
installed jumper and install the normally open isolated contacts of the field supplied
Safety Flow Switch.
CH1 *
5
Local Central Heat Demand
– Not applicable for Water Heater Applications.
CH2 (LL) *
6
Lead-Lag Central Heat Demand
– Not applicable for Water Heater Applications.
S
en
s
or
DHW
7
DHW Tank Demand
–
Input requiring closure of terminals 7 and 10 to initiate a demand
for DHW. Switch made via isolated end switch (dry contact) from the storage tank
thermostat (Aquastat). Or optional Tank Sensor (P/N 84632), see Appendix A.
NOTICE:
Tank Sensor – when operating in a cascade system, the water heater controls
do not support the use of a tank sensor: a tank thermostat (switch) must be used.
OD
SENSOR *
8
Outdoor Temperature Sensor
– Not applicable for Water Heater Applications.
SYSTEM *
9
System Water Temperature
– Not applicable for Water Heater Applications.
SENSOR
COM
10
System Common
–
Common port for field inputs DHW, OD Sensor and System Sensor.
4
-20mA
11
External Modulation Control
– Using a 4-20mA signal, an external control can be used
to directly modulate the burner firing rate or adjust the active set point. This can be
useful for applications using external staging controls or Building Automation Systems.
12
Com
m
u
n
ic
a
ti
o
n
s
LL DATA+
13
Lead-Lag
–
Connects internally to the controller’s MB2 Modbus communication port.
Terminals 13, 14 and 10 (common) can be "daisy-chained" to multiple water heaters (up
to 8 in total) for the purpose of staging.
LL DATA-
14
BMS D+
15
Building Management System (BMS)
– Connects internally to the display’s COM2,
Modbus communication port. Terminals 15, 16 and 10 (common) can be connected to a
Gateway for communication to a BMS or other device.
BMS D-
16
ALARM
17
Normally Open Alarm Contacts
– Contacts close during a lockout or other alarm
condition. May be connected to a BMS, maximum capacity of 0.63Amps at 24VAC.
18
