2.
SAFET
Y
Electrical Safety
CAUTION
Always turn off the power to the COM5 PT1 before removing the high voltage area Perspex
guard. Never touch wiring or components inside the high voltage area with the power on.
Always turn off the power to the COM5 PT1 using the mains switch and the battery isolation
switch before removing or replacing
any PCB’s
.
Always take basic anti-static precautions when working on the electronics, i.e., wearing a
wristband with an earth strap.
240 Volt
The COM5 PT1 is powered by 240-volt AC mains power. The mains power enters the cabinet via
a gland in the base and is connected into the main circuit breaker on the DIN rail. From the
circuit breaker, power goes to a connector block where it is split with wires running to the
thermostat/heater and to the power supply mounted on the back of the electronic module. The
power supply steps down the 230 Volts AC to 16-volt DC to power the main electronic
components.
Technicians should be able to safely operate and diagnose an COM5 PT1 with the cabinet door
open if they do not touch any of the 230 volt powered components behind the Perspex cover or
the 230 Volt terminals on the power supply.
Turning off the mains power at the mains circuit breaker should be sufficient to allow
maintenance of the COM5 PT1 providing isolation is tested.
The 2 DIN rails hold 230 Volt components. The 230 Volt components (230 Volt connector block,
circuit breaker, thermostat, and heater) should not be touched unless isolated. The 5 Volt wires
on the left-hand side can be safely touched to help diagnose connection problems.
CAUTION
The cabinet heater operates when the temperature inside the cabinet drops below a pre-set
level. In cold weather the heater can start without warning and may get hot enough to cause
skin burns if touched (105°C).