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eggs
29-09-2004, 04:45 PM
I have been asked to re-install one Ram18 to 2 RAS9's.(an old r22 system)
By looking at the electrical connections, it appeares that the outdoor unit has each of its compressors fed by a 13 amp supply from the indoor unit.
Sorry if this is a daft question, but i havn't seen it done like this before.
Is this correct ?
If so, and they are totally independant circuits, do you have simultaneous haeting and cooling ?

The RAM-30 CW1 that is the same age and also needs re-installing, has the more conventional 30a to outdoors, then powered interconnections.

Am i missing somthing ?

cheers

eggs

chemi-cool
29-09-2004, 05:21 PM
Hi eggs.

Is it a split unit with one condensing unit and one evaporator?

Chemi

chemi-cool
29-09-2004, 05:36 PM
Hi eggs.

Found this link, might be helpful
http://www.hitachi-hk.com.hk/FileManager/EN/ProductManager/air_con.pdf
Chemi

eggs
29-09-2004, 07:37 PM
Hi chemi.
it is a multi split, with 2 indoors to one outdoor.
cheers

eggs

chemi-cool
29-09-2004, 09:02 PM
Ok eggs.

Usualy there are two compressors in the outdoor unit.

and the power supply is also to the outdoor unit.

In that case, you can have one unit cooling and the other on heating mode. Very simple and basic.

Chemi

chemi-cool
29-09-2004, 09:21 PM
Hi eggs.

Very sorry about that link, just realized its in Chinese.

I'll try to find a better one.

Chemi :)

chemi-cool
29-09-2004, 09:59 PM
Try this one,
http://www.hitachiaircon.com/hac/files/attachments/PDF/DualEcoService.pdf

Chemi :)

frank
30-09-2004, 12:53 PM
In that case, you can have one unit cooling and the other on heating mode. Very simple and basic.

I don't see any reversing valves on the schematic Chemi - it looks like a cooling only system :confused:

chemi-cool
30-09-2004, 04:01 PM
Hi Frank.

I guess you are right.
I didnt all the pages, it would take me ages to download it.
My connection is not very fast, more of giving eggs the idea of what it is .

Chemi

frank
30-09-2004, 05:37 PM
By looking at the electrical connections, it appeares that the outdoor unit has each of its compressors fed by a 13 amp supply from the indoor unit.

This is a very common way of doing it Eggs - most of the old Marstair, Qualitaire etc. units do it this way. Basically the mains is fed from the outdoor to power the indoor fan then a switched live feeds back out to run the compressor through the stat/relay. The MCU range of IMI condensing units still does it this way.


If so, and they are totally independant circuits, do you have simultaneous haeting and cooling ?

If you had reversing valves and seperate condensers then yes but this unit has a shared condenser and is cooling only