Teledyne 9060 Operating Instructions Manual page 33

3.6 HEATER INTERLOCK RELAYS
Explosion protection for heated probes is achieved by switching the power to the probe
heater off whenever the main fuel valve is closed.
The principle of safety is that if the main fuel valve is open then main flame has been
established. With this primary source of ignition on, the probe heater can be safely
switched on. The most dangerous situation is if fuel leaks into the combustion appliance
when the fuel valve is closed. When power is removed from the main fuel valve the heater
should also be switched off.
To achieve this protection, connect a main fuel valve voltage free contact to the 'BURNER
ON SWITCH' terminals 18 & 19. When the main fuel valve is open, the voltage free
contact should be closed. For installations where there is no risk of explosion, connect a
link between terminals number 18 & 19.
Heater Supply Interlock Connection for Heated Probes
If a safety interlock is not required, a wire must be connected between terminals 18 &19 to
enable –
• The heaters on heated probes
• Process alarms
• Auto-purge and auto-cal checking.
3.7a CONNECTING AN OXYGEN PROBE CABLE
Connect the probe lead as shown in the following drawings. Unheated probe leads have
integral reference air tube. An adaptor has been supplied to connect this tube to quarter
inch flexible PVC tubing, from the air pump or reference air supply.
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9060-Zirconia Analyser
CAUTION
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