Ramsey Oretronic IV Tramp Metal Detector REC 4479C
Page 53
WARNING.
High voltage that may be present on leads could cause electrical shock.
•
All switches must be OFF when checking input AC electrical connections, removing or inserting
printed circuit boards, or attaching voltmeters to the system.
•
Use extreme caution when testing in, on, or around the electronics cabinet, PC boards, or
modules. There are voltages in excess of 115
–
230 V in these areas
—
even with the main door
open.
Testing the Transmitter Coil
Follow this procedure to test the transmitter coil if your system does not have a junction box.
1.
Turn off power to the control unit (main switch)
2.
Disconnect the transmitter coil wires from the field terminals marked Transmit.
3.
Measure the resistance of the coil.
If the ohmmeter does not show 2-3 ohms, the transmitter coil is bad.
If the transmitter coil resistance is approximately 2-3 ohms, the transmitter coil, its wiring, and its
portion of the CPU board is working correctly.
If your system uses a junction box, follow this procedure to test the transmitter coil:
1.
Turn off the power to the system control unit (main switch).
2.
Disconnect the transmitter coil wires from field terminals 4 and 5.
3.
Measure the resistance of the coil.
4.
If the transmitter coil resistance is approximately 2-3 ohms, the transmitter coil wires, the transmitter
coil, its wiring, and its portion of the CPU board are working correctly.
5.
If the Ohmmeter does not show 2-3 ohms, on the transmitter coil, measure the resistance between
terminal 24 and 25 at the junction box. If 24-25 at the junction box are 2-5 ohms, the cable from the
junction box to the control unit is bad.
Testing the Receiver Coil
Follow this procedure to test the receiver coil if your system does not have a junction box:
1.
Turn off power to the control unit (main switch)
2.
Disconnect the receiver coil wires from the terminals marked “Coil 1”.
3.
Measure the resistance of the coil. IF the resistance is greater than 500 ohms, the receiver coil is bad.
If the receiver coil resistance is approximately 450 to 500 ohms, the receiver coil, its wiring, and its
portion of the CPU board is working correctly.
If your system uses a junction box, follow this procedure to test the receiver coil:
1.
Turn off power to the control unit (main switch).
2.
Disconnect the receiver coil wires from terminals 121 and 222 at the junction box.
3.
Measure the resistance of the coil. If the resistance is greater than 500 ohms, the receiver coil is bad.
If the receiver coil resistance is approximately 450 to 500 ohms, the receiver coil, its wiring, and its
portion of the CPU board are all working correctly.
4.
If the receiver coil resistance is correct, reconnect the wires to the terminals in the junction box.
