IX Wiring

WARNING

All wiring and grounding must be done in accordance with the authority having jurisdiction or, in the absence of such requirements, with the National Electrical Code (ANSI/NFPA 70).

1)Line Voltage (120 VAC) Connections (Fig 9.1) – The line voltage connections are located in the junction box on the right side of the vestibule:

•Black – Line voltage “hot”

•White – “Neutral” for boiler and circulators

•Red – “Heating” circulator “hot”

•Blue – “Indirect Water Heater “ circulator “hot”

•Green – Ground connection

2)Maximum circulator continuous current draw is 2A. When Piping Method #1 is used, it may be desirable to use the boiler to directly control the primary circulator in addition to the secondary circulator. If this is done, control both heating circulators using a relay with a 120VAC coil, such as a Honeywell R4222, as shown in Figure 9.3. Select a relay with a contact rating in excess of the combined draw of the two circulators.

3)Low Voltage Connections (Fig 9.1) – These connections are screw terminals located on the terminal strip next to the junction box on the left:

•Terminals 1 and 2 – “Heating” thermostat connections

•Terminals 3 and 4 – “External Limit Control” connections

•Terminals 5 and 6 – “Outdoor Reset Sensor” connections

•Terminals 7 and 8 – “Domestic Indirect Water Heater” thermostat connections

•Terminal 9 – “Flame Signal Reading”

•Heat anticipator setting for the thermostat connection is 0.1 A when thermostat is connected directly to terminals 1 and 2.

CAUTION

•WHEN MAKING LOW VOLTAGE CONNECTIONS, MAKE SURE THAT NO EXTERNAL POWER SOURCE IS PRESENT IN THE THERMOSTAT OR LIMIT CIRCUITS. IF SUCH A POWER SOURCE IS PRESENT, IT COULD DESTROY THE BOILER’S MICROPROCESSOR CONTROL (MCBA). ONE EXAMPLE OF AN EXTERNAL POWER SOURCE THAT COULD BE INADVERTENTLY CON- NECTED TO THE LOW VOLTAGE CONNECTIONS IS A TRANSFORMER IN OLD THERMOSTAT WIRING.

4)If the outdoor sensor is connected to terminals 5 and 6, the boiler will adjust the target space heating set point supply water temperature downwards as the outdoor air temperature increases. If used, this sensor should be located on the outside of the structure in an area where it will sense the average air temperature around the house. Avoid placing this sensor in areas where it may be covered with ice or snow. In general, locations where the sensor will pick up direct radiation from the sun should also be avoided. Avoid placing the sensor near potential sources of electrical noise such as transformers, power lines, and ﬂuorescent lighting. Wire the sensor to the boiler using 22 gauge or larger wire. As with the sensor, the sensor wiring should be routed away from sources of electrical noise. Where it is impossible to avoid such noise sources, wire the sensor using a

2 conductor, UL Type CM, AWM Style 2092, 300Volt 60°C shielded cable. Connect one end of the shielding on this cable to ground.

BWC Series specifications

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The BWC Series employs a high-quality, stainless steel heat exchanger, which not only enhances performance but also extends the lifespan of the boiler. This heat exchanger is designed to transfer heat efficiently, ensuring that the maximum amount of energy from the fuel is converted into usable heat. Additionally, the design helps to prevent corrosion and maintain system integrity over years of usage.

For technological advancements, the BWC Series incorporates a modulating gas valve which allows for precise control over the boiler's operation. This feature enables the system to adjust its output based on the heating demands of the home, resulting in improved energy efficiency and consistent comfort levels. Moreover, this modulating technology reduces the frequency of cycling, thereby prolonging the lifespan of the unit and minimizing wear and tear.

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