Inspection and Maintenance Chapter 7
750-177 7-7
It is imperative that the gauge cocks are mounted in exact alignment. If they are not, the glass will be strained
and may fail prematurely.
A blowdown cock is provided on the lower gauge glass fitting and a daily blowdown is recommended.
Electrical Controls
The operating controls should be inspected monthly. Examine the tightness of electrical connections and keep
the controls clean. Remove any dust that accumulates on the interior of the controls using low pressure air
that is free of moisture and oil. Take care not to damage the mechanism.
Examine any mercury tube switches for damage or cracks. Dark scum over the normally bright surface of the
mercury indicates a damaged tube that may lead to erratic switching action. Make certain that controls are
correctly leveled. Covers should remain on controls and panels at all times. Dust and dirt can cause excessive
wear or overheating of the motor stator and the relay contacts, and affect operation of other controls. The
power supply to the boiler must be protected with dual element fuses (fusetrons) or circuit breakers. Similar
fuses should be used in branch circuits. Standard one-shot fuses are not recommended.
Flame Safeguard Control
This control requires minimal maintenance because the safety and logic sections are integral and inaccessible,
with no accessible contacts. Regularly check to see that the retaining screws holding the chassis to the
mounting base are secure, and that the amplifier and the program module are securely inserted.
It is recommended that a spare control be kept on hand and service be rotated between the active and the
spare control (programmer).
Note: Be sure that the connecting contacts on the control and the base are not bent out of position.
When replacing a control, be sure to lock out the main power supply, since the control is “hot” even
though the burner switch is off. Failure to heed this warning could result in serious personal injury
or death.
Your spare control should be wrapped in plastic and stored in a dry atmosphere. During an extended shutdown
(for example, a seasonal shutdown), the active control should be removed and stored in a dry atmosphere.
Moisture can cause problems with control operation.
The flame detector lens should be cleaned as often as operating conditions demand. Use a soft cloth
moistened with detergent to clean the lens.
A safety check procedure should be established to test the complete flame safeguard system at least once a
month. Tests should verify safety shutdown and a safety lockout upon failure to ignite the main flame and
upon loss of flame. Each of these conditions should be checked on a scheduled basis. Refer to the burner
manual for information regarding tests of the flame safeguard system. Contact your local Cleaver- Brooks
authorized representative for assistance, if required.
Checking Loss of Flame
With the burner in normal operation at the low fire rate, shut off the main burner fuel valve to interrupt the
fuel supply and extinguish the main flame.
The relay must signal the loss of flame, resulting in the fuel valve(s) being deenergized. The control will lock
out on a safety shutdown. The flame failure light (and optional alarm) will be activated. The blower motor will
stop.
Turn the burner switch off. Reset the safety switch. Reestablish the main fuel supply.
To Next Page
Loading...
Need help?
General
