CleaverBrooks WB, Owner'S Operation And Maintenance Manual

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Operating Instructions
4-4 750-136
Model WB Electric Boiler Manual
4.2 — Maintenance Schedule
4.2.1 — Weekly Procedure
Tighten the main supply lugs every 24 hours during the first week of operation.
4.2.2 — Quarterly Procedures
While the boiler is operating, lower the temperature setting drastically on the temperature control and listen for
the magnetic contactors to open. Then return the setting to normal and again listen for the magnetic contactors
to operate.
Turn off the control pilot switch and the main power supply switch. This is done as a safety measure to prevent
accidental turn-on of power.
Tighten all the electrical connections that could have loosened due to heat expansion and contraction. Pay par-
ticular attention to the main lugs that receive the power circuit. Examine all the relays and the magnetic contac-
tors for pitting, corrosion, burned or welded contacts, or inoperative 120 volt coils. Inspect for blown fuses or
discoloration of fuse clips, which would indicate a loose fit. Correct malfunctions as required.
If all the elements have been operating normally and each element bank draws its rated current or amperage,
where:
AMPS (3-phase) = Watts
Volts x 1.73
or
AMPS (single phase) = Watts
Volts
no further element tests are necessary. However, if there is a low or unbalanced amp reading, further tests with
an ohmmeter may be necessary to detect the open or shorted element(s) in the group. To test individual ele-
ments for continuity with an ohmmeter, the jumpers between elements must first be removed.
NOTE: Only personnel who have a working knowledge and understanding of this equipment should have access to
the control cabinet.
Lockout and disconnect the boiler’s main power to avoid the hazard of electrical shock, which could result in serious
personal injury or death.
When checking the element terminal connections, use wrenches on both nuts to avoid twisting the terminal stud and
damage to the equipment.
! Warning
! Caution