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PAGE 28
2472 DI HEATER OPERATION / MAINTENANCE MANUAL
ITEM
DETAILS
Temperature
Control
After the system has stabilized, the temperature reading indicated by
the controller process temperature should track very closely with the
temperature reading indicated by the controller setpoint temperature.
This visual check should be made weekly.
Heater
Element
Visually check the ELEMENT STATUS LED. The LED should not be
illuminated.
Plumbing
Leaks
Visually check DI water lines outside of heater cabinet for signs of
leaks at the connections. (A leak sensor will detect leaks, but this
periodic visual check is recommended.) Also visually check leak tray
(if applicable) or bottom of cabinet inside heater module enclosure for
DI water leaks. Tighten fitting(s) if necessary. If heater module is
leaking, contact Trebor for instructions.
Overpressure
Relief Drain &
Diaphragm
Visually check the drain line for water running from the heater. The
overpressure burst fitting can start leaking if the system has seen
pressures above 60 psig. The burst fitting can be checked by
inspecting the relief port at the back of the cabinet. No water should
be present in the relief drain since it is required to be plumbed to an
open drain. If water is present in the drain plumbing, the fitting should
be removed.
General
Electronics
Visually check electronics inside control enclosure for any signs of
overheating, deformation, or corrosion.
Fuse Blocks
The fuse holders should be free of corrosion and should not have
signs of overheating or deformation. All wire terminations on fuse
blocks should be tight. Any blown fuses should be replaced.
Solid State
Relays
The SSR’s should be free of corrosion at the terminals and should not
have signs of overheating or deformation. The wires attached to the
SSR’s should be clean and in good condition. Check and tighten
mounting screws for optimum heat transfer to heatsink.
Main Circuit
Breaker
The main circuit breaker should be checked for signs of loose
connections at the termination lugs. Damaged lugs should be
replaced. The terminals should be checked for tightness.
Main
Contactor
The main contactor should be checked for signs of loose connections
at termination lugs. Damaged lugs should be replaced. The
terminals should be checked for tightness.
Distribution
Block /
Terminal
Block
The distribution block / terminal block should be checked for signs of
loose connections at the termination lugs. The terminals should be
checked for tightness.
7.4 HEATER CALIBRATION
Due to heat loss and other external factors that effect the DI Water
temperature after it leaves the heater, it is not critical to precisely
calibrate the DI heater process temperature to closer than 1
C. For
highly critical process application, the heater temperature calibration
should be checked annually for possible degradation of sensors and or
temperature controllers over time. If a significant error occurs (> 5
C),
consult the factory for replacement parts.
The calibration method compares the output DI Water temperature to the
DI heater temperature controller process value. Perform the following
procedure:
Turn heater power off and isolate plumbing connections to allow
insertion of a temperature sensor.
