Weil-McLain 550 MBH Nstallation And Operation Manual page 50

®
SlimFit Series 3
Field wiring
electrical power supply at service entrance panel before making
any electrical connections to avoid possible electric shock hazard.
Failure to do so can cause severe personal injury or death.
The installation must comply with National Electrical Code and
any other national, state, provincial or local codes or regulations.
In Canada, CSA C22.1 Canadian Electrical Code Part 1, and any
local codes.
Wiring must be N.E.C. Class 1. If original wiring as supplied with
boiler must be replaced, use only type 105 °C wire or equivalent.
Boiler must be electrically grounded as required by National
Electrical Code ANSI/NFPA 70 – latest edition.
Do not use 24V from transformer to power any external devices
that are not listed in this manual.
Wire entrances
Eight knockouts are provided in the top of the cabinet for line
and low voltage wiring. See Figure 51 for locations.
Failure to do so can cause severe personal injury, death or sub-
stantial property damage.
Wiring overview
See details on the following pages for the wiring connections
outlined below:
Required wiring connections
120VAC power to boiler; 120VAC power out to boiler circula-
tor; system supply and return temperature sensors.
Connections as needed by systems
Thermostat, end switch or other inputs for call for heat.
System zone circulators, valves, relays, etc.
System circulator, when required.
Outdoor temperature sensor.
Optional wiring connections
External limits; proof-of-closure interlocks (combustion air
damper, flow switch, etc.); 0–10VDC for target or modulation
control; remote alarm; additional heat demand contact; and
communication cables for boiler networking and/or building
management system interface (MODBUS).
50
COMMERCIAL CONDENSING GAS
— For your safety, turn off
through jacket knockouts.
—
-
FIRED WATER BOILER
Wire entrances
Boiler Manual
Wire entrances
Part number 550-100-168/0516