Field Wiring; Line Voltage Connections; Low Voltage Connections; Outdoor Temperature Sensor - Weil-McLain ULTRA ULTRA-105 Service Manual

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GAS FIRED WATER BOILER SERIES

Field wiring

ELECTRICAL SHOCK HAZARD —
For your safety, turn off 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.
Wiring must be N.E.C. Class 1. If origi-
nal wiring as supplied with boiler must
be replaced, use only type 105°C wire
or equivalent. Boiler must be electri-
cally grounded as required by National
Electrical Code ANSI/NFPA 70 – latest
edition.
Install field wiring before venting to allow
easier access to terminal strips.
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.

Line voltage connections

1. Connect 120 VAC power wiring to line voltage terminal
strip in left compartment of electrical entrance, as shown
in Figure 2, page 5, item 1.
2. Provide and install a fused disconnect or service switch
(15 amp. recommended) as required by the code. (See
Routing field wiring
Terminals are numbered from left to right
when facing front of boiler.
4
—
1 & 2
Figure 2, page 5, item 2)
3. Boiler circulator is shipped loose. Wire Boiler circulator as shown for Fig-
ure 2, page 5, item 3.
4. When connecting a DHW circulator, connect wiring to line voltage terminal
strip as shown for Figure 2, page 5, item 5.
5. Route all wires and conduits to the jacket openings specified in Figure 1.
Wiring a system circulator
1. To activate a system circulator when the Boiler circulator operates, add a cir-
culator relay and wire as shown in Figure 2, page 5.
2. You must install a relay as shown. DO NOT wire in parallel with the Boiler
circulator. See CAUTION in Figure 2, page 5.

Low voltage connections

1. Connect low voltage wiring to low voltage terminal strip (Figure 3, page 5,
item 1) as shown in Figure 3 and the boiler wiring diagram.
2. Route all low voltage wires through grommeted jacket opening to right of low
voltage terminal strip, as shown in Figure 1.
Thermostat
1. Connect Figure 3, page 5, item 2, room thermostat or end switch (isolated
contact only) between terminals 5 and 6.
2. Install thermostat on inside wall away from influences of drafts, hot or cold
water pipes, lighting fixtures, television, sun rays, or fireplaces.
3. Thermostat anticipator (if applicable):
a. If connected directly to boiler, set for 0.1 amps.
b. If connected to relays or other devices, set to match total electrical power
requirements of connected devices. See device manufacturers' specifications
and thermostat instructions for details.

Outdoor temperature sensor

1. Connect outdoor temperature sensor (Figure 3, page 5, item 6) between ter-
minals 1 and 2 to enable outdoor reset operation of the Ultra boiler. If fixed-
temperature operation is required, do not install outdoor sensor.
2. Mount sensor on an exterior wall, if possible the North wall, shielded from
direct sunlight or flow of heat or cooling from other sources.
3. If desired, install a summer/winter switch (Figure 3, page 5, item 7) across ter-
minals 1 and 2. When the switch is closed, the boiler (space heating) circulator
is disabled.
4. Route sensor wires through the hole at the right of the electrical entrance (see
Figure 1).
DHW aquastat
1. Connect storage indirect water heater (DHW) aquastat (Figure 3, page 5, item 3)
between terminals 3 and 4.
Additional limits
1. Connect additional limit controls and interlocks between the terminals shown
in Figure 3, page 5.
2. Controls connected between terminals 6 and 7 (see Figure 3, page 5, item 4) will
cause a soft lockout (automatic reset). When limit(s) closes, boiler will resume
normal operation.
3. Controls connected between terminals 6 and 8 (see Figure 3, page 5, item 5)
will cause a hard lockout (manual reset). The boiler will only restart after the
Ultra display panel RESET switch is pressed.
Part number 550-100-029/0810