Wiring - Crown Boiler BSI Series Installation, Operating And Service Instructions

• 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).
• Electrical power may be supplied from more than one circuit. Disconnect electrical power to the boiler and
heating system before servicing. Positively assure that no voltage is present. Lock electrical boxes to
prevent someone from inadvertently restoring power before the heating system is safe to operate.
• Never defeat or jump out safety devices.
• Protect each boiler circuit with a properly sized over-current protection device.
• Make electrical connections carefully according to the boiler's wiring diagram and instructions. Failure to
properly wire electrical connections to the boiler may result in serious physical harm or property damage.
• Wire additional field supplied safety limits, such as low water cut-offs and pressure limit devices, so as
to break the 120V power supply to the boiler. Do not alter the boilers factory wiring when adding a field
supplied limit device.
1) 120 Volt Wiring - The boiler should be provided with its own 15A branch circuit with fused disconnect. All 120 volt
connections are made inside the junction box on the right side of the boiler. Remove the transformer to gain access to this
box (also see Figure 10.1):
•
Hot ("black") - Wire nut to black transformer lead
•
Neutral ("white") - Wire nut to white transformer lead
•
Ground ("green" or bare) - Ground screw inside junction box.
2) Thermostat Wiring - Follow thermostat manufacturer instructions. To insure proper thermostat operation, avoid installa-
tion in areas of poor air circulation, hot spots (near any heat source or in direct sunlight), cold spots (outside walls, walls
adjacent to unheated areas, locations subject to drafts). Provide Class II circuit between thermostat and boiler. Connect
thermostat wire leads to the blue transformer lead and brown relay lead inside the junction box. Set the heat anticipator
to 0.2A.
• When making low voltage connections, make sure that no external power source is present in the
thermostat circuits. If such a power source is present, it could destroy the boiler's control. One example
of an external power source that could be inadvertently connected to the low voltage connections is a
transformer in old thermostat wiring.
• Do not attempt to connect a McDonnell & Miller model #101A feeder, or other feeder without a delay,
to a BSI boiler equipped with a Hydrolevel CG400 low water cutoff. Doing so could destroy the boiler
transformer and/or flood the system.
• Do not use the transformer provided on the boiler to power external devices other than the feeders
specified in (3). Doing so may cause damage to the transformer.
3) Feeder Wiring – If an automatic water feeder is connected to the boiler, use one of the models listed below. Do not alter
any of the factory wiring on the boiler. Connections are made as follows:
a) Hydrolevel VXT-24 THREE-WIRE feeder:
• Connect the BLACK lead on the feeder to terminal 1 on the LWCO
• Connect the WHITE lead on the feeder to terminal 2 on the LWCO
• Connect the RED lead on the feeder to terminal A on the LWCO
b) McDonnell & Miller WF2-U-24 feeder:
• Connect terminal W on the feeder to terminal A on the LWCO
• Connect terminal N on the feeder to terminal 2 on the LWCO
• Connect terminal H on the feeder to terminal 1 on the LWCO
X Wiring
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WARNING
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CAUTION
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