Riley air conditioning

Ron Ball · #1 06-10-03, 08:12 PM

My Riley air-conditioning circuit breaker pops when AC air is turned on . The 10 amp breaker pops.. The fan turns on . I disconnected the wire to the electric clutch, on the condensor and the breaker is O.K. Called Tule River where they installed it and they said is an automotive type and need to replace. They mentioned to check the diode on the unit, can't find it.Anyone have this problem? The breaker pops immediately , so it appears to be a short. Would a bad diode cause this? If I can find the diode[ not on the schematic] can it be replaced , without taking out the condensor?

MikeZ · #2 06-10-03, 10:46 PM

Call SuperSkyrocket LLC at (800) 841-1115. I have installed a number of Riley mods on my P337, including AC (works great) and I've found their tech service to be excellent.

kevin · #3 06-11-03, 08:35 AM

Tule River is Skyrocket LLC's shop, they do all their installs/remanufacturing now, unless something has changed recently. So I think Ron is already talking to the people that know this mod best these days...

Kevin

Bob Cook · #4 06-11-03, 08:49 AM

Oh Yes....... Riley Airconditioning..

1) Diode is on top of the compressor connector. If you pull the compressor solenoid connector at the compressor the breaker should pop if the diode is bad or there is a short to ground in the harness.

2) These breakers are not all that accurate. Put an ammeter in the circuit and measure the current.

3) Try turning the thermostat switch to "no air conditioning" and see if the breaker pops when you increase the "cold" setting. IF so then you have narrowed it to the compressor solenoid.

4) You may need to do a resistance check on the coil at the compressor. I rather doubt they have put the diode on the coil side of the solenoid connector. Check for shorts at the compressor.

5) The compressor is an automotive type that is used by Chrysler. I do not have the schematic in front of me but I think they use a resistor in series with the compressor coil as the coil is 12 volts and the aircraft system is 24 volts. The resistor may be mounted up on the rear firewall if I remember correctly.

BTW the fan is connected thru the squat switch on the gear and thru a relay. When the gear comes up the condenser fan quits running. IT should run on the ground. It is fused or breakered seperately from the coil and evaporator fan.

hope this helps

Bob

Ron Ball · #5 06-11-03, 05:55 PM

Thanks, bob and all. i called Riley and Richard was very helpfull. He will send a schematic and work with me to get this fixed. Bob do you know if the electric clutch is normally opened or closed. Want to check to see if it is shorted. Also, to check to see if the diode is bad, do I need to take it out,? this would mean desoldering it and unscrewing it and then testing.

Bob Cook · #6 06-11-03, 10:57 PM

Ron

Clutch is normally de-energized. You can take a couple of cables and apply voltage directly to solenoid (12v not 24volts) and you should hear it energize. (disconnect the harness plug on the aircraft at the compressor solenoid.

You can take an ohm meter and see there is current in one direction and not the other. if there is a short in the diode you will get a very low resistance in either direction (reversing probes).

You need to find out it the diode is on the compressor or in the harness at the compressor. It is used to cut the reverse EMF (energy) which destroys the switch as the coil is an inductive load.

You can measure the resistance on the one in your car and it should be the same as the one in the aircraft. Should be just a few ohms.

The schematic is really simple. The voltage (24v) is fed to the switch in the overhead and then goes to the thermostat switch then to the solenoid (also thru a low pressure cut out switch which is normally closed when system is pressurized). It is that simple.

It is rarely the coil in the solenoid would short. more likely the solenoid or the wire is chaffed and is shorting to ground somewhere between the thermosat switch and the solenoid.

Remember to do the test with the thermostat off and see if it blows the breaker when the thermostat is moved towards cool (should hear the switch click when it is moved and is calling for cooling).

hope this helps.

Bob

Ron Ball · #7 06-12-03, 01:19 PM

Thank you Bob. Richard from Riley said that the new ones, sounded like since 98 or so are now 24 volt windings in the clutch.They got rid of the resistors.