conditioning units require a certain RCD mcb Breaker type and rating
Since the advent of
Inverter heat pump air conditioning there is the
occasional problem with electrical RCD breakers going out
due to rating issues. Because inverter air conditioning units
use a DC driven compressor there can be issues with the transfer
from AC to DC which creates a lot of EMF thus causing the RCD
mcb breaker to blow, the inverter board uses the Hertz supply
going to the compressor to reduce or speed it up and for some
reason low rated i.e 30mA RCD's have a rating problem.
The biggest problem
with a underrated RCD breaker is that it can be a periodic
issue, i.e the air conditioning units work for 2 months then all
of a sudden a issue arises where the supply blows. The obvious
first thought is that the inverter air conditioning unit itself has a
major problem such as a PCB or compressor fault. This can waste
valuable site time and customer down time while a fault is
attempted to be rectified and on occasion parts being replaced.
The now obsolete but
easier to electrically supply, fixed speed air conditioning
systems used a direct on line motor compressor, either the compressor was
Off or On according to the thermostat requirements. This made
them a easer to rate electrically as they were a inductive rated
load which usually meant using a C type breaker with no
consequence to a RCD. The fixed speed models produced no high
output EMF because there were no inverter boards inside the outdoor
unit with heavy electronic board based triacs and coils
producing heavy electrical noise.
Which RCD Breaker Is
Use With Inverter Air Conditioning
It is best to use a
(greater than) 100mA RCD breaker as this will give the
electrical supply sufficient support to hold in while the air
conditioning inverter system ramps up and slows down. Many
electricians are unaware that air conditioning systems require a
rating high than 30mA and it has to be said most of the time a
30Ma RCD will work. But if you are a electrician of air
conditioning engineer with a issue with a RCD which keeps
blowing it just might not be rated for the project.
+44(0)845 567 7080 For air
conditioning project quotations.