Ultra Boiler Manual
Part number 550-100-440/0122
94
pump or another boiler is available.
Connect to remote alarm, when used
Connect wiring for multiple boiler operation
• e U-Control provides the exibility 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
• e boiler is shipped with an outdoor sensor, a
system supply sensor and a system return sensor.
e system supply sensor will be required for most
space heating applications. e system return sensor
must also be installed when using the system supply
sensor. Use of the outdoor sensor is optional.
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
Figure111,page96 and above.
1. e 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. See Figure110,page95.
The maximum allowable current for each
circulator is 2.2 amps at 120 VAC
. For
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.
2. You can connect any of the circulators you use to any of
the three circulator activation terminals. e U-Control
setup allows you to assign which circulators activate on
a call for heat (this can be customized for each of the
heating systems supplied by the boiler).
3. e U-Control factory
default settings for DHW heat-
ing are congured for direct piping to the boiler, with
Circulator 1 being the only circulator being activated
during DHW heating. To use factory default settings,
1. e U-Control provides plug-in, color-coded, non-interchange-
able terminal strips for all eld wiring. See the schematic diagram
(Figure111,page96) & ladder diagram (Figure112,page97).
2. e U-Control provides programmable exibility in system op-
eration, allowing control of heat supply for up to three dierent
heating systems. Read this manual thoroughly before connecting
the wiring to ensure trouble-free start-up and operation.
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 dierent circuits are available — e U-Control will
require manual reset for one of these circuits. e U-Control
will automatically reset aer limit operation and re-closure
for limits in the other circuit.
Connect thermostats and/or heat demand contacts
• e U-Control can regulate the boiler for up to three dierent
heating systems.
Connect remote operation input, if used
• e 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
• e U-Control allows the boiler to act as the primary or sec-
ondary heat source when another heat source, such as a heat
ELECTRICAL SHOCK HAZARD — For your
safety, turn o 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.
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.