Q-SERIES DI HEATER OPERATION / MAINTENANCE MANUAL
PAGE 23
alarming. If the fault condition is not corrected before the delay period
expires, the heater will progress to an alarm state (see section 5.2.b).
NOTE: The default timeout period is 30 seconds. Contact factory for
instructions on how to adjust this time delay.
The liquid level interlock utilizes an optical sensor to detect water level. It
is critical that this sensor operate properly. Do not tamper with the
sensor. Damage to the system can result if the sensor is altered.
6.3 ELEMENT OVER TEMPERATURE SENSOR
A temperature limit controller monitors a thermocouple attached to a
heater element in each of the heater modules. In the event an element
temperature exceeds the normal operating temperature, the ability to
heat water will immediately be disabled and the system will go into an
alarm state. If this occurs, check element continuity before continuing
normal operation (see section 8.1.a).
NOTE: Running the heater at the maximum temperature set point and at
a flow rate that requires 100% power for extended periods can lead to
intermittent over temperature alarms. Reducing flow or temperature set
point slightly will correct the problem.
6.4 LIQUID LEAK SENSOR
If a liquid leak is detected in the bottom of the heater cabinet, the ability
to heat water will immediately be disabled and the system will go into an
alarm state. Fix any leaks and dry the leak sensor and leak tray prior to
turning power on to the system.
6.5 OVERPRESSURE RELIEF FITTING
The overpressure relief
fitting “Relief Drain” is connected in-line with the
cold DI inlet port to provide a mechanical safeguard against possible
damage from operating the heater with a fluid pressure above 414 kPa
(60 psig).
If the overpressure relief device opens, the low fluid pressure sensor will
alarm. A periodic visual inspection of the fitting is recommended. Refer
to Section 8.1.f for instructions on replacing the relief fitting.
