Fulton Vertical Electric (FT-N) Thermal Fluid (hot oil) Heater - Manual (Page 57)

Fulton Thermal Corp.*Electric Thermal Fluid Heaters Manual* Version 2010-0423
Page 57
3. Temperature controllers measure the bulk temperature and not the film
temperature. This must be taken into consideration when setting the
temperature controls.
4. These approximate guidelines for temperature settings are not to
override the system design parameters.
5. These instructions should be used with information from the system
designer. Manufacturer’s literature on the temperature controller is
provided in the last section of this manual.
6. Standard primary temperature control sensing point location for On/Off
and Modulating heaters is on the heater outlet.
7. When optional inlet location of the primary controls is specified. the
following instructions may still be used with some modification. For
instance when primary controls are located on the inlet, the dead band
range will be much narrower than on heaters with outlet control. In
addition, temperature changes will not be as immediately apparent.
8. An indicating temperature controller is used to regulate the thermal fluid
temperature. Typically the indicating control is a thermocouple.
9. The thermocouple is directly immersed in the thermal fluid in the heater
manifold. The setpoint of the controller is regulated by the keypad.
g) High Temperature Limit Switches Safety (All units)
1. All units are fitted with high temperature limit controllers which monitor
the fluid temperature at the heater outlet. This limit controller provides
over temperature protection. A high temperature limit switch acts as an
over temperature safety device. If the high temperature limit shuts down
the unit, the manual reset button on the limit switch must be pressed.
The red button on the flame programmer must also be pressed to reset
the unit before it can be restarted. The high temperature limit controller is
factory set to 0°F. This must be set to the lowest of the following:
a. Maximum operating temperature of the fluid.
b. Maximum operating temperature of the equipment.
c. 15°F over maximum system operating temperature.
2. Do not set this controller too close to the normal outlet temperature in
order to avoid nuisance lockouts due to small transient over
temperatures.
3. Several consecutive lockouts caused by the high temperature limit
controller indicate the need for immediate installation review, beginning
with fluid level in the expansion tank, firing rate, and circulating pump
performance.