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View Full Version : FNISHED! Recharge 410 and TXV Repair ( " they" said it couldnt be done)



daveca
24-07-2023, 09:54 PM
Trane XL14C 3 Ton package

Recharge R410A

*CHARGED VAPOUR

*WITH COMPRESSOR OFF

*Repaired broken TXV Thermostat bulb

* Recharged bulb with 410 vapour

*NO SEALED SYSTEM WORK TO FIX THE TXV

Works perfectly:

https://m.youtube.com/watch?v=H8s6NkkvMLg

135 psi low side, +/- a little, depending on entering air conditions.

170 psi R410 on the TXV bulb
hi 80F outdoor
mid 70F indoor
50% RH
nominal about 11.7 amp total package current,
Cycle time at 74F indoor, 950 S.F. two level, with airflow problems, 10 minutes


Interesting to note the main function of the thermostatic assembly is to shut the TXV at compressor off, obviously to preserve the liquid line contents.

The diaphragm pressure at the bulb only affects the low side pressure up to a point.

That is the stated low side pressure by the P&T cycle data from Trane. Increasing bulb presure past the point of stated low side pressure has little or no effect. The system pressures are controlled by indoor and outdoor temp and RH factors, not TXV operation.

This TXV only has a control movement of 0.020 inch, so it appears to be more of an Off- On than a flow regulator.

The info I received from this and other Internet forums was UNIVERSALLY WRONG.

Info from Sporlan Tech was WRONG.

Engineering, thermodynamics and chemistry knowlege told me to ignore it.

I was right.

Grizzly
25-07-2023, 10:44 AM
Well Done You!
However if your posts are continually going to criticise any and everything that someone posts. I for one will not weep if you take further issue and refrain from contributing.
I am sure your style of contribution would be more appreciated maybe on the american forum.
We are all here to help one another.
Grizzly

Rob White
25-07-2023, 11:00 AM
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Some Expansion valves have a critical charge that acts as a capacity control.

The charge in the bulb is reduced to stop the valve opening fully. In startup conditions or
during high load situations the valve can't fully open due to the restricted charge in the bulb.

Just one point I noticed from your video. Did you connect the bulb to the evaporator outlet so it sensed the refrigerant temp of the outlet of the evap?

The video did not make it clear but it looked like you left it swinging in the airflow??

Rob

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