Power; Boiler Pump; Dry Contacts; Alarm Bell - Bradford White OmniTech BONH1250 Installation And Operation Instructions Manual

7.E.1

Power

7.E.2

Boiler Pump

If connecting a boiler contactor or pump, use terminals
17 (neutral) and 18 (line voltage). The output of these
terminals is 120VAC with a maximum output current of
1.5 amps. Boiler pump functionality is configured using
the touch screen. (See 8.D.5 on page 78)
The controller energizes the appropriate pump contacts
when it receives a call for heat. Once the call for heat is
satisfied, the pumps will remain on for the defined pump
overrun time.
The boiler pump is fed 120VAC internally from the main
power feed. The current rating of this output is 2.5A
maximum at 250VAC. The system and DHW pump
outputs are dry contacts, both with current ratings of
1.5A maximum at 250VAC. An appropriately sized
contactor must be supplied and installed by a qualified
technician for each of these outputs. Pump functionality
is configured using the touchscreen.
7.E.3

Dry Contacts

DHW Pump - when connecting a domestic hot water
(DHW) pump, use terminals 19 and 20. As this is a dry
contact, the DHW pump supply voltage or DHW pump
relay coil voltage would be applied at terminal 19, and
when the DHW pump is activated, would be available
at terminal 20. Contact ratings are 250VAC, 1.5A
maximum. DHW pump functionality is configured using
the touch screen.
System Pump - if connecting a system pump, use
terminals 21 and 22. As this is a dry contact, the system
pump supply voltage or system pump relay coil voltage
would be applied at terminal 21, and when the system
pump is activated, power will be available at terminal 22.
Contact ratings are 250VAC, 1.5A maximum. System
pump functionality is configured using the touch screen.
Spare 1 and Spare 2 - no functionality available on this
unit.
7.E.4

Alarm Bell

If connecting an alarm bell, use terminals 27 and 28.
As this is a dry contact, the alarm bell supply voltage is
applied at terminal 27, with the alarm bell connected to
terminal 28.
7.E.5

Sensors

System Supply - if used, is connected to terminals 29
and 30. When connected, the controller automatically
detects the presence of this sensor and the temperature
is shown on the home screen above the red system
supply arrow. When installed, the unit controls the firing
rate to maintain the system supply temperature to the
heat demand set point (or CSP) and hysteresis.
When running the Power and Field Connection
wiring between the units (Cascade, System
Sensor, Outdoor Sensor, Building Automation,
Etc), always Exit and Enter the wiring through
the lower back panels so that during future
servicing, the wires are not in the way and do not
have to be disconnected in order to remove the
top and side panels.
Lors de l'exécution du domaine d'alimentation et
les fils électriques de connexion entre les unités
(Cascade, Capteur, système capteur extérieur,
domotique, etc), TOUJOURS quitter et entrer les
unités à travers la partie inférieure arrière de sorte
qu'au cours de l'entretien futur, les fils ne sont pas
dans la voie et n'ont pas à être déconnecté afin
d'enlever le haut et le côté.
System Return - if used, is connected to terminals 31
and 32. When connected, the controller automatically
detects the presence of this sensor and the temperature
is shown on the home screen above the blue system
output arrow.
Domestic Hot Water (DHW) - if a tank sensor is used,
connect to terminals 33 and 34. When connected, the
unit will automatically detect the presence of this sensor
and perform the DHW thermostat function based on the
settings selected at DHW or DHW3 parameter screens.
The temperature is displayed on the home screen below
the faucet icon. The controller initiates a call for heat,
maintaining the set point within the on and off hysteresis
selected at DHW or DHW3 demand screen, without any
need for jumpers.
Note: The Heat Demands at 33 to 34 are used for sensors
only, aquastats would be applied to the "Heat Demand"
terminals 41 and 42 (see Heat Demands section below).
Outdoor - if used, is connected to terminals 35 and 36.
When connected, the controller automatically detects the
presence of this sensor and the temperature is shown on the
home screen as the Outdoor Ambient Temperature (OAT).
If installed, options such as outdoor reset and warm
weather shutdown can be enabled through the display.
Always install the Outdoor Sensor at an outdoor location
that is not affected by false temperature readings such as
sunlight or hot equipment.
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