Fault Finding - Benchmark PulsaCoil A-Class 145 Design, Installation And Servicing Instructions

3.0 SERVICING

3.4 FAULT FINDING

appliance control panel and printed circuit control board/display
A-CLASS
The PulsaCoil
have been designed to be fully automatic whilst able to provide functional and diagnostic
information to the householder/installer.
The panel/board work in conjunction with a number of sensors (thermistors) located as
shown in the diagram below.
Automatic Control Operation
Heating of the store is controlled by sensors S1/S2 and S5 and S6.
During normal charging cycle sensor S5 will control the bottom off peak I.H. (on 60ºC
off 70ºC ) in the same way S6 will control the top on peak I.H. when manually activated
( on 65ºC off 70ºC).
In the event of either of these sensors failing, control will be taken over by sensors S1/S2
(on 60ºC off 70ºC ).
Normally, sensors S1/S2 are used to detect an overheat condition (over 95ºC) which will
cause the red LED on the front control panel to flash (rapid).
This condition should not normally be reached as sensors S1/S2 will also switch off
the supplies to the I.H's if a temperature above 85ºC is detected. Normal operation will
automatically resume when the temperature at the sensors drops below 78ºC.
The hot water temperature is controlled by sensors S3 and S4.
S3 checks for a drop in temperature every second and if the drop is more than 2ºC , it
switches on the hot water pump to raise the domestic hot water temperature to 52ºC
(± 2°C).
The control of the hot water temperature is carried out by sensor S4 adjusting the speed
of the hot water pump.
The pump is stopped once S3 reaches a temperature of above 30°C.
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