gledhill TEC140-OV Installation & Servicing Instructions Manual page 44

SERVICING AND MAINTENANCE
Electrical power connections
Reference schematic
opposite
Power supply to PWM
Controller PCB
Check inputs to the PWM Controller PCB
Reference schematic
opposite
CW temperature sensor
TS temperature sensor
HW temperature sensor
Flow sensor
FAULT FINDING
Check procedure
Electrically isolate power supply at fused spur switch and remove fuse.
Earth continuity test (dead test) – to ensure that the appliance is earthed
Mains voltage test (dead test) - to ensure that the appliance is isolated
Resistance to earth (dead test) – to ensure that the wiring insulation to the product is intact
Short circuit test (dead test) – to ensure that no components in the products circuit have a short circuit
Visually inspect wiring is correct as per fig 4.3
Connect supply
Polarity test (live test) - to ensure that the live is connecter to the live etc
• Check 230V ac across L1 to Earth
• Check 230V ac across L1 to N
• Check for 0 to 15V ac N to earth
Reference to "Boilerfault finder.com" gives clear instructions to on how to perform these tests. (Menu
options 1st. Boiler Fault finder 2nd. Electrical safety checks).
Check procedure
Power off
Disconnect J18
Measure and record the resistance across terminals 6 and 13
Measure the cold water inlet temperature
Compare the resistance measured with chart "Tasseron NTC 12k thermistor"
The reading should make sense taking measurement conditions into consideration
Power off
Disconnect J18
Measure and record the resistance across terminals 3 and 10
Measure the thermal store temperature
Compare the resistance measured with chart "Tasseron NTC 12k thermistor"
The reading should make sense taking measurement conditions into consideration
Power off
Disconnect J18
Measure and record the resistance across terminals 7 and 14
Measure the Hot water temperature
Compare the resistance measured with chart "HUBA combined flow sensor and NTC 10k thermistor"
The reading should make sense taking measurement conditions into consideration
Power off
Disconnect J18
Power on Sensor required a power supply 5 VDC
Open a HW tap and set to a flow rate.
Measure and record the frequency across terminals 1 and 12
Compare the frequency measured with chart "flow rate determination"
The reading should make sense taking measurement conditions into consideration
Page 44