City Multi 6607 fault.

[eire1]

Hey folks. I have a call to a Mitsubishi City Multi, a 6607 fault. It's a vrf system: 15 indoors, 2 bc boxes and 2 condensers. I managed to get a shot of the remote/fault in a self check. Any ides where to start with identifying the cause of the fault? Sorry about the size of the photo, no idea how to resize it.
Thanks
Attachment 12105

[Brian_UK]

Start with the fault code list...
www.orionair.co.uk/PDF/Mitsubishi_elec_Fault_codes.pdf

[eire1]

6607 is listed as "Communication issue - no response back from unit whilst system is operational"
Does the 101 and Grp.RC info that i got from the self check help narrow it down at all??

[hyperion]

It might mean that the power has been turned off to one of the air handlers or it could be that one of the air handlers is incorrectly addressed. The 101 might refer to the actual remote controller nearest to the fault. A fair bit of time will be needed to gradually eliminate the source of the fault. It is also possible that a virgin restart might clear the problem. Lots of thing to check and try.

[install monkey]

check for interference on the m net 30v dc, check tightness of connections, check indoor units are powered up

[eire1]

All 15 units are working, good off coil temperatures. I'm getting 28.5v DC on my m-net. One of the BC boxes is right above a metal detector, maybe that's creating noise?

[eire1]

We've only recently started on a lot of Mitsubishi city multi. I was told a virgin restart is to kill all indoors, bc and outdoors then after, you turn them back on in the order: indoors, outdoors then bc boxes. Is this correct?

[JP6]

6607 can mean a lot of things, can be very difficult to get to the bottom of.

Is it one system? As in the 2 outdoors twinned > master BC > slave BC > 15 indoors? Is is addressed properly? Central controller?

You've confirmed you have 17-30VDC MNET at each indoor so there doesn't seem to be any transmission wiring missing. MNET can be sensitive to noise. Is any of the transmission wires over 200m?

I'd try a virgin restart to rule out any commissioning errors first as follows:

- Power everything down
- At the outdoor unit flick SW2-2 ON (deletes all saved info)
- Power up outdoor unit until LD8 illuminates
- Power off again and flick SW2-2 OFF
- Power up indoors, BC then outdoor unit

[eire1]

6607 can mean a lot of things, can be very difficult to get to the bottom of.

Is it one system? As in the 2 outdoors twinned > master BC > slave BC > 15 indoors? Is is addressed properly? Central controller?

You've confirmed you have 17-30VDC MNET at each indoor so there doesn't seem to be any transmission wiring missing. MNET can be sensitive to noise. Is any of the transmission wires over 200m?

I'd try a virgin restart to rule out any commissioning errors first as follows:

- Power everything down
- At the outdoor unit flick SW2-2 ON (deletes all saved info)
- Power up outdoor unit until LD8 illuminates
- Power off again and flick SW2-2 OFF
- Power up indoors, BC then outdoor unit

Yeah it's exactly as described above: twinned condensers, master and slave BC. It's 100% addressed properly, I double checked it myself. There is no central controller.
Do I need to flick SW2-2 on both condensers?

[JP6]

Yes do both.

[eire1]

Did both, still no joy. I noticed that none of the units have anything in the S (shield) on the indoors. I reckon the fault is caused by this.

[martinw58]

you can get a problem if you don't use the shield from the out door all the way to the last indoor

[Neddy]

Some engineers don't connect in to the S terminal and just twist the shields together and cover with insulation tape.The shield should be earthed at the lowest addressed outdoor. Has anyone removed or changed a controller?

[eire1]

No sign of the shields being connected on any of the indoors. Definitely no controllers have been moved or replaced. It's turning into a nightmare call.

[JP6]

We've had an indoor PCB failure produce a 6607 that wouldn't go away. In the end we had to keep removing units from the MNET one by one until the fault disappeared and we found the unit at fault.

[regcooldude]

Hey folks. I have a call to a Mitsubishi City Multi, a 6607 fault. It's a vrf system: 15 indoors, 2 bc boxes and 2 condensers. I managed to get a shot of the remote/fault in a self check. Any ides where to start with identifying the cause of the fault? Sorry about the size of the photo, no idea how to resize it.
Thanks
Attachment 12105

Have you considered an m-net booster? Your mnet cabling maybe too long

[ballvalve]

If system is still running as normal its more then likely no power to sub outdoor .This causes a 6607 fault but system still runs at 50%

[install monkey]

isnt the 101 referring to the 1st unit rc?

[Neddy]

I would agree with install Monkey. The Controller in the picture looks like a PAR-30/31 which doesnt connect to the M-Net. I would look at indoor address 1 and check if the controller connected to this unit is in the M Net. Also the address rotary dials of the controller causing the 6607 fault will be 0 & 1 (address 101).

[regcooldude]

I would agree with install Monkey. The Controller in the picture looks like a PAR-30/31 which doesnt connect to the M-Net. I would look at indoor address 1 and check if the controller connected to this unit is in the M Net. Also the address rotary dials of the controller causing the 6607 fault will be 0 & 1 (address 101).

Neddy, there is no address dials on a par 30 /31 only on the par27's. if this controller was on the m-net it simply wouldn't work. It requires 12vdc not 29vdc

[Neddy]

Regcooldude,

If you read my post correctly I have said a PAR 30/31 doesn't connect to the M Net. If you get 6607 101 the system can't see the controller 101 which controls the unit addressed number 1. The system must have a PAR 27 connected or someone connected a PAR 27 and removed it.

[JP6]

Or a PAR-U02 which is the new ME controller that does connect to the MNET. Check unit address 1 to see what's wired where, possibly connected a MNET controller and not addressed it.

[eire1]

It's a PAR30. It's a new site so there was definitely never a Par-27 connected. The controller runs Units 1 and 2. Both units work fine, with great off coil temperatures in all modes. Both had 28.5v DC on the M-net. The client was happy to leave it for now since the system is running, he doesn't want to pay to stay on site to investigate further.
I'm back on site in August for a maintenance so I'll have another look then.

[JoeAT50A]

Seem like ME controller (PAR-F27ME or SmartME) 101 had connected/registered before.
You need to use ME remote controller (101) to register with one of the indoor unit first and delete registration properly.
After deleted you could able to see "HO" sign, then you can safely remove your ME remote controller from Mnet line.
Hope this help.