Field Wiring - Weil-McLain Ultra Manual

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gas fired water boiler

Field wiring

ELECTRICAL SHOCK HAZARD
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 78, page 55) & ladder diagram (Figure 79, page 56).
2. The U-Control provides programmable flexibility in system op-
eration, allowing control of 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
Connect 120VAC power (minimum 15-amp source)
❏
Connect wiring for up to three circulators
❏
Connect external limits, if used
❏
• 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.
Connect thermostats and/or heat demand contacts
❏
• The U-Control can regulate the boiler for up to three different
heating systems.
Connect remote operation input, if used
❏
• The U-Control will operate and modulate the boiler based
on a 0–10 VDC control signal from a remote controller, when
desired.
Connect the "additional heat demand" circuit to a second
❏
heating source, when used
• The U-Control allows the boiler to act as the primary or sec-
54
— Boiler Manual
(see Figure 78 & Figure 79)
— For your
.)
ondary heat source when another heat source, such
as a heat pump or another boiler is available.
Connect to remote alarm, when used
❏
Connect wiring for multiple boiler operation
❏
• 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.
Install system & outdoor sensors, when used
❏
• 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
1. Provide and install a fused disconnect or service switch
(15-ampere rated recommended) as required by ap-
plicable codes.
2. Connect minimum 15-ampere, 120 VAC power wiring
to Ultra boiler line voltage terminal strip as shown in
Figure 78, page 55 and above.
Wiring circulators
1. The U-Control provides for connection of up to three
circulators, one of which must be the boiler circulator.
In addition, you can connect a system circulator and a
DHW circulator, for examples.
The maximum allowable current for each
circulator is 2 2 amps at 120 VAC
circulators with higher amp ratings, you must
install a circulator relay or starter to provide
line voltage to the circulator. For circulators
rated over 2.2 amps, connect only the circula-
tor relay or starter coil to the Ultra circulator
terminals.
Continued after page 56
. For
Part number 550-100-066/0608