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marc5180
21-09-2008, 02:46 PM
Was called out to a problem this morning, "the air conditioning not working". When i got to site i found power to 2 of the condensors (there are 3 condensors feeding 6 indoor units) with no power to the 3rd.
Went upstairs to the control panel where the controllers where mounted and found a breaker tripped for the condensor.
I turned the breaker back on and put all of the controllers into cooling 19DegC whilst holding the sensor on the return air of each indoor unit but none of the outdoor units kicked in.
I went to the outdoor unit and on the back of the cover it said to move DSW1 switch1 to on and this would put it in emergency cool..... but again nothing kicked in.
I have power on each of the indoor and outdoor boards but they are the new hitatchi's which i haven't had much dealings with.

How do i put the controller on test mode or is this not possible? The model number of the controller is PCP 2HT and the condensor is an Hitatchi RAS8HRNM, any help would be appreciated.
Thanks guys

Thermatech
21-09-2008, 05:58 PM
The outdoor circuit board may need to see a minimum compressor temperature before allowing it to start.
The CCH is at the bottom of the comprerssor & the temp sensor is at the top & it can take quite a few hours for the top of the compressor to get up to the required temp I think it is about 40 deg C.
So if you left the power on to the outdoor units then when you go back it will be ready to go.

Daddy Cool
22-09-2008, 12:40 PM
Marc5180, assuming the units were working when commissioned, it may be worth downloading the Hitachi Technical or Service manual for the IVX range from hitachiaircon.com; just a thought, but the IVX range is quite new, so was it your lads that installed it, or was it someone else who's now run for the hills?

marc5180
22-09-2008, 09:47 PM
Sorry i've only just replied back, i lost my internet connection last night and couldn't get back online.

Thermatech you were right as always. The place has just been built and the power supply to the building was not big enough, so until a new power supply was fed into the building the builders hired a generator, which the air conditioning units were on.
At night the generator was turned off, which turned off the condensors- which cut the power to the crankcase.

As soon as the oil warmed up (which took 3 hours) the units kicked into life and began cooling.

There are quite a few problems on this site, which is due to be handed over to our company to look after very soon.
One of them being a 10 breaker that trips every so often. The single phase breaker is a ring main for the indoor cassettes and the pumps. The sparks have checked for faulty wiring and measured each indoor amperage and fully loaded they all measure 4 amps but yet it still blows.

Brian_UK
22-09-2008, 10:42 PM
May not apply Marc but is the MCB suitable for motor starting ?

I know that the indoors are only small but if a few kick in at once .........

Is there a d i c k y pump somewhere ?

marc5180
23-09-2008, 07:34 PM
To be honest Brian, i dont know anything about the job. We will be taking over the site soon so as soon as we do we will be checking the place over but at the minute it's not our place.
First thing i will be checking though is the breaker and all of the pumps.