Fulton Vertical Electric (FT-N) Thermal Fluid (hot oil) Heater - Manual (Page 68)

Fulton Thermal Corp.*Electric Thermal Fluid Heaters Manual* Version 2010-0423
Page 68
a) Review log sheets and note any deviations from the norm.
Annually
a) Clean all the strainers in the thermal fluid system.
b) Take a quart sample of thermal fluid and have it analyzed per fluid manufacturers
instructions.
c) Schedule the local representative or factory technician to perform preventative
maintenance on the system.
Note
All of the above maintenance procedures should be completed by trained
personnel. Appropriate training and instructions are available from the Fulton
Service Department at (315) 298-7148 or your local Fulton Thermal Representative.
6. Troubleshooting
Flow Circuit/Circulating Pump(s)
a) The flow circuit is the electrical circuit that enables the circulating pump(s). Your thermal
fluid pump(s) will remain on until the flow circuit opens to disable the pump starter or the
Off / Pump / Heat switch is turned to the "Off" position.
b) Items in the flow circuit may include paddle type flow switches, a high inlet pressure
switch, a low inlet pressure switch, a high outlet pressure switch and a differential
pressure switch.
c) Low Inlet Pressure Switch
1. All N-Model heaters have a Low Inlet Pressure Switch. This is a
normally open switch that closes with proper heater inlet pressure.
This switch is generally a mercury bulb type switch. Mercury will rest
towards the green cap of the mercury bulb in a "made" condition.
2. The purpose of the Low Inlet Pressure Switch is primarily to protect
the heater from a low flow condition. The Low Inlet Pressure Switch
should be set at 5 psi below normal heater inlet pressure as read at
operating temperature assuming that none of the conditions
mentioned below are true. A tripped Low Inlet Pressure Switch is an
indication of one of the following.
3. If your Low Inlet Pressure Switch is not making, check the following
items:
d) Plugged circulation pump strainer basket
1. A plugged strainer will result in a decrease of flow through the
heater. High vacuums developed from plugged strainers can also
stress the seals of the pump causing the pump to fail.