ac Contactors in split ac outdoor unit

[kefah]

hi every one
i have question about the ac relay Contactors in split unit
i bought two split unit both are 2 ton capacity
from same type nd model
one has Contactors in the outdoor unit
the other not
when i checked the wiring diagram
i found that the company had removed it
so the compressor is work directly from the pcb in the indoor unit without Contactors
what is the difference if there is Contactors in outdoor unit or not

[martinw58]

is there a contactor on the id door pcb for the compressor

[kefah]

is there a contactor on the id door pcb for the compressor
soory for mistake
no there is no contactor in the id pcb

in both split unit i bought
but there is relay in the id pcb
in both split

[monkey spanners]

Some run off the indoor board with suitably sized relay, and some have a small relay on the indoor board and a contactor on the outdoor unit.

[kefah]

Some run off the indoor board with suitably sized relay, and some have a small relay on the indoor board and a contactor on the outdoor unit.

thanks
but the two split are same type and model
both have relay in indoor pcb
but one have contactor in outdoor unit other not

[install monkey]

if the wiring diagram shows there should be a contactor, fit one :)

[kefah]

if the wiring diagram shows there should be a contactor, fit one :)

its look like the company has removed the contactor
so what is the problem if it been removed
the compressor type is reciprocating

[install monkey]

the thermostat- mechnical or pcb will take the full load of the compressor, not ideal, mechanical stat(ranco c17) will take upto 20 amp pcb will be less more chance of welding the contacts

[Brian_UK]

Maybe they didn't have a contactor to replace a broken one, I do not know why it broke so please don't ask.

Just fit one to get it back up to standard.

[kefah]

the thermostat- mechnical or pcb will take the full load of the compressor, not ideal, mechanical stat(ranco c17) will take upto 20 amp pcb will be less more chance of welding the contacts

you mean the pcb will be in danger of damage due to high current
the relay is 20 amp 250 volt
can it withstand the compressor load or not

[kefah]

Maybe they didn't have a contactor to replace a broken one, I do not know why it broke so please don't ask.

Just fit one to get it back up to standard.
no they are not broken
the old production of these unit was contain contactor
in the new production the whole split dont contain contactor
i will fit one
but i asked why did that
and what are the disadvantage

[install monkey]

if the newer version doesnt have a contactor then they may have fitted a bigger indoor relay to compensate, if the manufacturers have done this then all is ok, just that its not unusual for an unskilled person to remove the contactor and bodge it

[kefah]

if the newer version doesnt have a contactor then they may have fitted a bigger indoor relay to compensate, if the manufacturers have done this then all is ok, just that its not unusual for an unskilled person to remove the contactor and bodge it

no man
they didnt fit larger relay
the pcb is same
and relay in both split are same

[install monkey]

2 ton - 7 kw is quite a bit for a pcb relay, old uk units(fujitsu) used to have a 20amp power relay in addition to the pcb relay in the indoor- on a 3kw unit that runs at 4 amp but peak start up current was 30amp!!! im guessing your unit is non inverter, with no soft start kit

[kefah]

2 ton - 7 kw is quite a bit for a pcb relay, old uk units(fujitsu) used to have a 20amp power relay in addition to the pcb relay in the indoor- on a 3kw unit that runs at 4 amp but peak start up current was 30amp!!! im guessing your unit is non inverter, with no soft start kit

its not inverter
there is only relay on pcb in indoor unit
relay is 20 amp 250 volt mx

[martinw58]

what is the make and model of the unit

[kefah]

what is the make and model of the unit
its crafft heatpump
24000 btu
http://www.crafft.co.uk/information.asp?show=5&id=2

[kefah]

ok
i found that the company removed the contact er due to save money
and this is not ideal
many pcb burned thanks to hi current drawn by compressor