Field Wiring - Weil-McLain Ultra Commercial Installation And Start-Up Manual

COMMERCIAL GAS

Field wiring

safety, turn off electrical power supply at service
entrance panel before making any electrical connec-
tions to avoid possible electric shock hazard. Failure
to do so can cause severe personal injury or death.
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.
Installation must comply with:
1. National Electrical Code and any other national, state, provincial or
local codes or regulations.
2. In Canada, CSA C22.1 Canadian Electrical Code Part 1, and any local
codes.
Wiring — general
1. The U-Control provides plug-in, color-coded, non-interchangeable
terminal strips for all field wiring. See the schematic diagram (Fig-
ure 57, page 52) & ladder diagram (Figure 58, page 54).
2. The U-Control provides programmable flexibility in system opera-
tion, allowing control of the heat supply for up to three different
heating systems. Read this manual thoroughly before connecting
the wiring to ensure trouble-free start-up and operation.
Wiring — overview
You will need to make the following connections, some of which
depend on your system and how the U-Control will be programmed.
(
See this and following pages for more information
Two different circuits are available — The U-Control will
require manual reset for one of these circuits. The U-Control
will automatically reset after limit operation and re-closure for
limits in the other circuit.
The U-Control can regulate the boiler for up to three different
heating systems.
The U-Control will operate and modulate the boiler based
on a 0–10 VDC control signal from a remote controller, when
desired.
Part number 550-100-086/0809
-
FIRED WATER BOILER
— For your
.)
— Boiler Manual
The U-Control allows the boiler to act as the primary
or secondary heat source when another heat source,
such as a heat pump or another boiler is available.
The U-Control provides the flexibility for control
of multiple Ultra boilers.
You will need to program the boilers' U-Controls
based on the interconnection method you choose.
The boiler is shipped with an outdoor sensor, a
system supply sensor and a system return sensor.
The system supply sensor will be required for most
space heating applications. The system return sensor
must also be installed when using the system supply
sensor. Use of the outdoor sensor is optional.
Line voltage power input
Line voltage and boiler circulator
connections
1. Boiler line voltage power — Boiler load is 18 amps.
Provide and install a fused disconnect or service switch
(25- or 30-ampere rated recommended) as required by
applicable codes.
2. Boiler circulator line voltage power — Provide and
install a fused disconnect or service switch (15-ampere
rated recommended) as required by applicable codes for
circulator with maximum load of 10 amps.
Boiler Circulator terminals
on expansion module
51