Mitsubishi Electric Query

[goldpau]

Hi all,

Went to a new customer today with a single outdoor unit connected to 4 x 7kw Ceiling mount indoor units (PCFY-P63VGM-A) - the data plate on outdoor unit has totally faded so cant see anything (no model number / refrigerant charge etc), theres a large R407c sticker on it so safe to assume its R407c.

Anyhow indoor cooling is pretty pathetic (theres 1 x controller which controls all 4 indoor units at the same time), so put guages on the outdoor unit and got the following: - suction 85psi (6bar), discharge 340psi (22bar) - outdoor temp today was 21C (used the ports located on left hand side of outdoor unit marked low/high pressure)

Must admit dont have too much experience with R407c so with poor cooling im thinking the system being R407c must have had a small leak and is now an improper blend in the system - am i on the right tracks?

Normally i would recover the refrigerant and check weight against data plate but seeing as theres no data plate i have nothing to compare to!

Cheers!

[install monkey]

is it single fan condenser city multi puryp200vgma- or ymfc im servicing some tomorrow- normally 8.5kg factory and you need to measure the pipework

[install monkey]

its inverter driven so pressures vary depending on load- check filters clean, coils clean, typically 58deg discharge temp 7deg suction and 24deg liq temp whilst running at 6.4amp on yellow phase

[install monkey]

If you check behind electrics cover it will give the model no, for a 200 and a 250 outdoor, 8.5kg for factory charge for a 250ymfc theres a sticker inside that should be labelled for indoors and additional charge, good luck

[goldpau]

many thanks for advice, filters were clean indoor coils clean but outdoor coils not in the best of condition as its located on the coast so the fins pretty well break off if theyre touched! going back to site later in week so will use info you have provided, its a single fan condensor

[AbsoluteWDJ]

Hi all,

Went to a new customer today with a single outdoor unit connected to 4 x 7kw Ceiling mount indoor units (PCFY-P63VGM-A) - the data plate on outdoor unit has totally faded so cant see anything (no model number / refrigerant charge etc), theres a large R407c sticker on it so safe to assume its R407c.

Anyhow indoor cooling is pretty pathetic (theres 1 x controller which controls all 4 indoor units at the same time), so put guages on the outdoor unit and got the following: - suction 85psi (6bar), discharge 340psi (22bar) - outdoor temp today was 21C (used the ports located on left hand side of outdoor unit marked low/high pressure)

Must admit dont have too much experience with R407c so with poor cooling im thinking the system being R407c must have had a small leak and is now an improper blend in the system - am i on the right tracks?

Normally i would recover the refrigerant and check weight against data plate but seeing as theres no data plate i have nothing to compare to!

Cheers!

22 bar high pressure is a little high R407c
6 bar low pressure is a little high for R407c

Is the outdoor coil blocked/soiled? Try cleaning/rinsing outdoor coil with gauge connected. See if you can get the head pressure down.

Is the outdoor fan motor operating correctly?

Regards

[goldpau]

Outdoor coil isn't blocked but it's not in good condition (salt corrosion) means the fins on the coil literally disintegrate if touched, (its over 90% in tact) outdoor fan motor turns but doesn't speed up and seems to turn slowly, from the controller I set the system to cool & 18c, on the display of controller it seems to show the current room temp - this didnt drop at all from 23c despite being on for over 1hour - poss over-charged system?? Or is it down to the poor condition of outdoor coil?

[install monkey]

my unit is working fine,coils cleaned- was running at 47htz in a 18deg ambient

22 bar high pressure is a little high R407c
6 bar low pressure is a little high for R407c

Is the outdoor coil blocked/soiled? Try cleaning/rinsing outdoor coil with gauge connected. See if you can get the head pressure down.

Is the outdoor fan motor operating correctly?

Regards

[AbsoluteWDJ]

my unit is working fine,coils cleaned- was running at 47htz in a 18deg ambient

R407c @ 22bar is around 50c condensing temperature - seems a little high to me
R407c @ 6bar is around 12c evaporating temperature - seems a little high also

Are you getting confused with R410a?