Lochinvar Power-Fin 502 Installation & Operation Manual page 44

5
Electrical connections
Figure 5-1_Line Voltage Field Wiring Connections
Low voltage connections
1. Route all low voltage wires through the knockouts in the
rear of the heater, as shown in FIG. 5-2.
2. Connect low voltage wiring to the low voltage connection
board as shown in FIG. 5-4 on page 46 of this manual and
the heater wiring diagram.
Figure 5-2_Routing Field Wiring
44
Installation & Operation Manual
EMS or remote thermostat connection
An EMS, remote thermostat or other remote
temperature control may be connected to the boiler
(see FIG. 5-3). Follow the manufacturer's instructions
supplied with the remote temperature control for
proper installation and adjustment. Connection of
a set of dry switching contacts or a remote on/off
thermostat to the low voltage connection board will
allow the unit to be switched on and off by making
or breaking a 24 VAC control circuit. Remove the
factory jumper between the enable terminals on
the low voltage connection board and connect the
remote temperature control in its place, see FIG. 5-4
on page 46.
Ensure that all wiring used to connect the switching
contacts of the remote temperature controller to
the connection board are a minimum of 18 gauge
and have a maximum installed length of 300 feet
(91.4m). Set the SMART SYSTEM control to a set
point temperature slightly higher than the setting
of the remote temperature control. This will ensure
that the remote temperature controller functions as
the operating control for the heater.
Figure 5-3_Remote ON/OFF Wire Connection
DHW (Domestic Hot Water) thermostat
1. Connect the DHW tank thermostat (FIG. 5-4) to the tank
thermostat terminals on the connection board.
DHW tank sensor
If a tank sensor is used, it must be connected to the tank
sensor terminals on the low voltage connection board. The
correct Lochinvar sensor (TST2032) MUST BE USED.