Getting 28 volts DC on terminals 5 and 6 (Resettable Power) of the D9124 fire panel. Every time that a smoke loop is connected to terminals 5 and 6 the voltage is dropping to 2 volts DC.
1.) First, make sure that the power supply is wired correctly. If both of the black wires are on output 2 negative of the D9142 then this could cause terminals 5 and 6 on the D9124 resettable power to decrease the voltage when a smoke loop is applied. To correct this problem place one of the black wires on output 1 negative and the other black wire on output 2 negative of the D9142 power supply.
2.) There could also be a wiring issue on terminals 5 and 6. Make sure that there is no shorts on these terminals. A short on these terminals will cause the same problem.
3.) Verify there is 24Vdc output with no wires connected.
Part numbers D9124, D9100, D9142, D9142F, D9124G, D914GV2