Toshiba RAV Series L29 Error

[blaze99]

Hello,

We got Toshiba RAV Series 6HP Ductible unit installed in our living area last year. We are experiencing unit shut down with L29 error on remote control after 15-20 minutes of operation.

The above said unit works perfectly fine when outside temperatures are at maximum of 38-39C. Since, we live in New Delhi where peak temperatures reach upto 45-47C in peak summers the unit stops working quite frequently during afternoon i.e. day time when temperature exceed 39C. We have noted that unit works perfectly fine during night when the outside temperature drops.

I have also noted that both the fans installed in the outdoor unit will stop working even before the L29 error is displayed/and the unit shuts down completely. Outside Fin temperature was noted at 40.3C on thermometer today when the fans installed inside outside unit stopped working

Since we're in Lockdown due to COVID 19, we are unable to get technical support from Toshiba. Any leads/solutions would be very helpful.

[frank]

This fault has been discussed before - here (http://www.refrigeration-engineer.com/forums/showthread.php?29998-Toshiba-RAV-series-L29-fault) is a link to it.

[blaze99]

Hello Frank,

The above thread is closed for me to put up further questions.

Also this is my first hand experience resolving AirCon issue and with little knowledge therefore I am looking for specific answers.

Following explanation was given for L29 error:

Error on outdoor unit, etc.
· Communication error between
CDB and IPDU
(Coming-off of connector)
· Heat sink temperature
error
(Temperature over specified
value was detected.)

Since the AirCon would work perfectly fine with temperatures below 39 I don't think there would be any problem in wiring i.e. Communication error between CDB and IPDU

Also my Condenser Coils are clean and shiny. If this is Heat Sink Temperature error I would request someone to guide me to resolve the issue.

[Brian_UK]

It is possible that the "heat sink" temperature is the problem due to the high ambient temperatures. The design limit for RAV units is 46⁰C and the control board is mounted underneath the top cover.

Service manual https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.toshibaclim.com/Portals/0/Documentation/Manuels%2520produits/SM_MuralKRTP-KRT_564804_GB.pdf&ved=2ahUKEwj9ne_InvfpAhXLEcAKHRrACHoQFjADegQIAxAB&usg=AOvVaw2ZaVWTtOHh-5uRhF49qJFF

See pages 50/51.

Can you provide some shade or reflective cover over the unit somehow?

[blaze99]

It is possible that the "heat sink" temperature is the problem due to the high ambient temperatures. The design limit for RAV units is 46⁰C and the control board is mounted underneath the top cover.

Service manual https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.toshibaclim.com/Portals/0/Documentation/Manuels%2520produits/SM_MuralKRTP-KRT_564804_GB.pdf&ved=2ahUKEwj9ne_InvfpAhXLEcAKHRrACHoQFjADegQIAxAB&usg=AOvVaw2ZaVWTtOHh-5uRhF49qJFF

See pages 50/51.

Can you provide some shade or reflective cover over the unit somehow?


Dear Brian,

Thank you for your response and link to this amazing servicing bible.

The outdoor Unit is installed in our apartment balcony and is mostly under shade other than couple of hours in morning.

Would be keen to know the ideal Heat Sink Temperatures when AirCon is operating. Currently, Outside temperature is 34C and AirCon is working perfectly fine.

I have noted outside heat sink temperature at 63 according to code 65 of servicing manual. Pic attached. Wondering if 63 is normal and also what are ideal temperatures of heat sink so that I can monitor again tomorrow when AirCon shuts down during day.

15580

[Brian_UK]

There is a document covering the IGBT component on the PCB but the details pass way high over my head.

https://www.google.com/url?sa=t&source=web&rct=j&url=https://toshiba.semicon-storage.com/info/docget.jsp%3Fdid%3D63557&ved=2ahUKEwjXloCr3vfpAhWEs3EKHcXADwYQFjAAegQIAhAC&usg=AOvVaw29zYpDtYhunq_DKg6iZrXG

It had some data with the chip at a rated ambient of 25⁰C where the max could be 125⁰C or 175⁰C depending on other factors.

I couldn't find anything specific to its use in the RAV.

Additional info ----

Found another manual with more fault finding on the L29 error code...

https://www.google.com/url?sa=t&source=web&rct=j&url=http://ilmalampopumput.fi/man/Toshiba%2520Service%2520Manual%2520RAV-SM%2520560%2520U-B-KR-XT-A%2520A02-014%2520rev%2520June%252004.pdf&ved=2ahUKEwjN-JHI4vfpAhWWi1wKHdT8An4QFjAGegQIAxAB&usg=AOvVaw1grBXCpWSRAT-9uGJHk3TV

See page 82.