trane rtaa 100

[michael26]

Have a rtaa100 that doesn't seem to load and unload correctly. I noticed that it wouldn't load so I replaced the load and unload solenoid valves that are next to each other but not the oil solenoid valve on the opposite side of the compressor. It starts fine unloaded and the unload coil stays loaded all the time. But I disconnected the load/unload connectors at the 1u5 board and connected the load wire to 110 and it loaded just fine but when I connected the unload wire to the 110 it didn't unload. It stayed loaded, the unload valve continued to stay energized. After I pressed the stop button the compressor did unload before shut down when it de-energized the oil solenoid on the opposite side of the compressor. Also the unload valve stayed energized even when the machine was trying to load and it would pulse the load coil. I understand that the board must be bad since it doesn't de-energize the coil. But why would the compressor not unload when the unload coil is connected to 110?

[just_opinion]

Have a rtaa100 that doesn't seem to load and unload correctly. I noticed that it wouldn't load so I replaced the load and unload solenoid valves that are next to each other but not the oil solenoid valve on the opposite side of the compressor. It starts fine unloaded and the unload coil stays loaded all the time. But I disconnected the load/unload connectors at the 1u5 board and connected the load wire to 110 and it loaded just fine but when I connected the unload wire to the 110 it didn't unload. It stayed loaded, the unload valve continued to stay energized. After I pressed the stop button the compressor did unload before shut down when it de-energized the oil solenoid on the opposite side of the compressor. Also the unload valve stayed energized even when the machine was trying to load and it would pulse the load coil. I understand that the board must be bad since it doesn't de-energize the coil. But why would the compressor not unload when the unload coil is connected to 110?

Please call a professional tech.

I am sure some will give you advice against the site rule. But, it is best that you follow my first advice.

[basshound71]

There are service bullitens on this issue depending on the age of the unit.

[michael26]

Call a professional huh. I have worked on these units for years and I never have seen this issue before, sorry I don't work for trane so I don't get service bulletins, but I would greatly appreciate it if somebody had a service bulletin number they could offer me or an explanation. I know there are plenty of trane gurus on here because every time I put a trane question on here it gets answered.
As for "just opinion" can you answer this question? From the looks of your other posts you might want to stick with the 5 tons or less posts.

[michael26]

Ok it looks like I do have the sb-4 but this is for the larger compressors. What sb do I need for the smaller compressors with the internal oil filters. If I had to guess I would saw 120 ton rtaas and below. thanks in advance.

[jayguy]

...As for "just opinion" can you answer this question? From the looks of your other posts you might want to stick with the 5 tons or less posts.

OUCH!

[jayguy]

Have a rtaa100 that doesn't seem to load and unload correctly. I noticed that it wouldn't load so I replaced the load and unload solenoid valves that are next to each other but not the oil solenoid valve on the opposite side of the compressor. It starts fine unloaded and the unload coil stays loaded all the time. But I disconnected the load/unload connectors at the 1u5 board and connected the load wire to 110 and it loaded just fine but when I connected the unload wire to the 110 it didn't unload. It stayed loaded, the unload valve continued to stay energized. After I pressed the stop button the compressor did unload before shut down when it de-energized the oil solenoid on the opposite side of the compressor. Also the unload valve stayed energized even when the machine was trying to load and it would pulse the load coil. I understand that the board must be bad since it doesn't de-energize the coil. But why would the compressor not unload when the unload coil is connected to 110?

the 'oil solenoid' is not an oil solenoid...it is the female unload solenoid...energized means unloaded...de-energized means loaded. so 'loading' and 'unloading' can be a relative term...so what is loaded in your world?

the solenoids energize and de-energize properly...so nothing wrong there.

as for why it won't unload when energized, it may have a pill filter plugged up, if the load solenoid is energized it might not energize...still kinda depends on what 'loaded' and 'unloaded' means to you.

[michael26]

Does the female unload solenoid stay energized the entire time the compressor is running until it starts to shut down? Can the pill filter be taken out to test and see if it is plugged up?

[michael26]

My rtaa-sb-4 is from 1992, is there a newer version that covers this smaller compressor or is there a different sb-# that I need all together.

[Healey Nut]

'loading' and 'unloading' can be a relevant term

I know when Im loaded and its usually a saturday night after a few cold ones ,
As for unloaded thats usually the day after a good vindaloo curry ............ put me another toilet roll on ice Honey please !!!!!!!!!!!!!!!!!!

[RichardL]

As for unloaded thats usually the day after a good vindaloo curry ............ put me another toilet roll on ice Honey please !!!!!!!!!!!!!!!!!!

I had to Google the "Vindaloo Curry" to see what Brer' Graham was speaking of...Sounds awesome to me.

[jayguy]

...As for unloaded thats usually the day after a good vindaloo curry ............ put me another toilet roll on ice Honey please !!!!!!!!!!!!!!!!!!

now THAT'S funny!

[jayguy]

Does the female unload solenoid stay energized the entire time the compressor is running until it starts to shut down? Can the pill filter be taken out to test and see if it is plugged up?

under 'low load' conditions, if the chilled water is satisfied or the leaving chilled water is being over-cooled, the female rotor solenoid will be energized to unload the compressor. it is energized at start up and at shut down no matter what, however, it is usually de-energized while running, but it can be energized the entire run cycle if conditions exist.

trane has recommended that the pill filters be removed whenever you remove the solenoids or you are in the compressor.

look for RTAA-SB-9 for more info

[michael26]

Ok so once the compressor is running then it doesn't use the male load and male unload to control the slide valve it actually uses the male load and the female unload? Why when the machine tries to load [(increase capacity)to keep jokes at bay] it pulses the male load solenoid you can see the amperage increase for the duration of the pulse then return to lower amperage, the male unloader solenoid never de-energizes. But if I disconnect the power from the male unloader and power the male loader then the amperage will increase and the suction pressure will drop (loaded, or an increase in capacity). Then if I remove power from the male loader and power the male unloader the compressor will never decrease capacity, then as the load decrease and the machine satisfies it can't unload(decrease capacity) and gets into the low saturation temp area 22 degrees I believe. Does this make sense, I know between graham and jay you know the answer. Also thanks for the heads up on the sb-9, I called trane today but they couldn't figure out which sb it was. Maybe this sb will explain it better for me, because I am trying to test it as it was a larger compressor with only the two solenoids. thanks in advance.

[Healey Nut]

because I am trying to test it as it was a larger compressor with only the two solenoids. thanks in advance.


Ok now were really confused ???

The small compressor (GP compressor ) has three solenoids . The large compressor only has two solenoids .
The small compressor has a step solenoid that takes it from 30 to 60% approx it then uses the two solenoids to vary the capacity from 60 to 100%
The large compressor should start at around 40% current and then varies using the two solenoids all the way up to 100%

Can I get back to my Vindaloo now please ???

[jayguy]

...Can I get back to my Vindaloo now please ???

she's gonna blow! everybody get out! wait, she's gonna blow...everybody get back in!


here is why we need model numbers. the RTAA100 is a smaller, 2 compressor chiller with 2, 50 ton compressors in it.

an RTAA chiller that is 200 tons or more can have 1 or more 100 tons each compressors in it.

the RTAA130 ton chillers (and larger) have 3 solenoid valves per compressor, 1 male rotor LOAD solenoid, 1 male rotor UNLOAD solenoid and 1 master oil solenoid (which is NOT mounted on the compressor).

the UNDER 130 ton chillers have 3 solenoid valves per compressor, 1 male rotor LOAD solenoid, 1 male rotor UNLOAD solenoid and 1 female rotor solenoid (which LOADS and UNLOADS) the compressor depending on its energized state...yes, it sounds confusing, however, after working with them for a minute or two, it is really pretty simple...don't over complicate them.

MODEL NUMBER OF THE COMPRESSOR IS: (here is where you quote me and fill in the model number of the compressor)

[AiResearch]

As for "just opinion" can you answer this question? From the looks of your other posts you might want to stick with the 5 tons or less posts.[/QUOTE]

[stanbyyourword]

Its the economy making people competitive