Hot Topics:

·        What is a Check 70?

·        How EOLR supervision is enabled/disabled:

·        Make sure the panel is properly mounted:

What is a Check 70?

Check 70 indicates that the control panel has sensed a trouble on the bell circuit.

The trouble could be caused by:

§         A short in the bell circuit (to ground or any other wire)

§         Voltage induced on the bell circuit

§         An open on the bell circuit if EOLR supervision is enabled (see below)

How EOLR supervision is enabled/disabled:

If you cut the red jumper right above the panel bell output, the panel will look for a resistor on the bell circuit.

The Vista-10/30 panels use a 1K-Ohm resistor.

The Vista-15/20 panels use a 2K-Ohm resistor.

If the red jumper is intact, the panel does not supervise for an open circuit (lost EOLR), but always supervises for a short or induced voltage.

Make sure the panel is properly mounted:

The control panel should mount with plastic spacers at the bottom of the PCB behind the mounting screws. (Between the PCB and the can)

If these are not installed, the PCB may short to the cabinet.

This is likely to short terminal 2(AC) to terminal 3(Bell+)