Ultra1000 Wireless Detectors
(Battery Operated)
Rev 2
Page 20
5.3 Replacing Sensor Head Assembly
Replacing the Stainless Steel sensor head assembly requires to dismantle the base circuit board
assembly from the bottom of the enclosure. However, does not require to disconnect the
antenna cable. The antenna cable is secured with a tie wrap and should not be disconnected from
the wireless transceiver on the bottom of the circuit board. Also precaution should be taken for
proper handling of the circuit board assembly.
Follow the procedure below to replace the sensor head assembly. See Figure 4 (next page),
bottom view of the circuit board assembly.
Power off the detectors as explained in section 1
Remove transmitter board assembly by detaching the ribbon cable connector
Remove the battery holding plate, disconnect and remove the battery from the base circuit
board assembly.
The circuit board is mounted inside the enclosure via 3 machine screws. Remove the
screws and slowly pull the circuit board out of the housing.
Pull and slowly flip the board upside down. Disconnect the four pin wire plug connecting
the sensor head wires from the circuit board. Let the circuit board hang aside on the
enclosure.
Unscrew the stainless steel sensor head assembly and detach it from the sensor junction
box.
Disconnect the wires from the 4-pin plug (Sensor Terminal). Connect the new sensor wires
on the plug.
****** Note the Color code of the wires connection to the plug ******
Engage the new sensor housing into the threaded entry of the junction box. . Lubricate the
threads slightly if needed.
Connect the 4-pin plug to the receptacle on the circuit board. Recheck the wires
connection confirm the color codes. Also make sure the ribbon cable is firmly connected
to the connector on the bottom of the PCB assembly.
