PDA

View Full Version : Hitachi RAS-20FSG strange problem with fuse



ewgeny
05-03-2010, 09:27 PM
Hi folks. There is a very strange problem with one Set-Free VRF RAS-20FSG system installed. There are no history documents and I'dont know what kind of problems were in the past and what repairments were done. The problem is that the system works for day or two, and stops with "no error code" (the client says that). They shut it of, wait for about an 1/2 hour and shut it on, evrything is back to normal for day or two. So, I opened it when it was stoped, and really there was no alarm code. I checked for last stop reason it was "32" - Abnormal transmissoin IU-OU.
Quickly I found a blown fuse EF2 on outdoor unit, changed and, restart but the system show alarm code 05 and won't work. Take off the fuse, and it's back - the systems work :rolleyes: - it works WITHOUT fuse, but with the fuse WON'T work.
On the next day, I tried to "give it" the new fuse again, and than nothing work, even the 7-segment display. Turn off power, take off the fuse, turn back power - OMG - it works. :confused:
I read in SM about DSW10, but I don't understand about which fuse is about.

The power supply is OK and L1 L2 L3 are in right order (it won't work at all if they are changed)

Does anyone see such a case??

PS: Sorry for my poor English.

philjd26
08-03-2010, 08:43 AM
Hi
strange one alright,however I would check for shorts and pcb track,diconnect all connections/jacks and plug everything in one at a time.....

Seems like a faulty board to me, as you said running! If not broken do not fix.

Rgrds phil

ewgeny
08-03-2010, 09:26 AM
Actually, there is something wrong, becouse the system stops after a few days working and have to restart it.
There is a switch (SW10) on OU and in the sevice manual says that if fuse is melted, have to correct the transmision wiring, put the switch on position and than change the fuse. But I can't understand for wich fuse is that mean. Does any one know more about the function of this SW10 ?
Thanks in advance