www.freedomhp.co.uk
©G Hendra Nov 18
19
Electrically testing the communications
With unit completely powered up but NOT
running
Set your multimeter to DC Voltage, and place
the probes on F1 and F2 on the indoor mim
PCB, If the voltage reading is fluctuating
between 160mV and 210mV the units are
communicating healthily and there is no
problem.
If the Voltage is 0V, you must remove the red
plug from the main PCB in the outdoor unit
and check the voltage across the pins on the
board. If the Voltage across the pins is
between 270mV and 300mV and fluctuating,
the outdoor PCB is fine and you need to look
at the cables between the indoor and outdoor
PBC’s.
There is a terminal block on the outdoor unit,
below the PCB, labelled F1 and F2, this is
where the communication cables between the
two units are wired into, if the voltage reading
across F1 and F2 here is between 270mV
and 300mV, the Red plug and Blue/red wired
are fine and you’ll need to check for a break
or short in the cables that run between indoor
and outdoor units.
If the voltage here is 0V, you’ll need to
replace the red plug/red and blue wires