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[QUOTE]Originally posted by mccool
[B]Alco or Sporlan? "Headmaster" is Alco so chances of valve failure is quadruple.


What a great line! Two thoughts, first if it is a self contained unit...

Gas charged powerheads are used to limit the opening of the TEV based on pressure. Usually there is no extra cost for this feature, but the pressure limit be be applied properly with the specific...

[QUOTE]Originally posted by gerryboy00
[B]when i am talking to a hvac tech. im talking "Tons" and operating pressure.

when i am talking to a reefer tech. im talking HP. and coils temperature. ...

It depends on the expansion valve type (specifically the thermostatic charge)as to whether a problem could occur. "Gas Charged" pressure limiting power heads are susceptible to "charge migration"; a...

danny x,

I'm not picking on you (and I did read your P.S.)so please don't take this the wrong way, but I completely disagree. This is the refrigeration board and while superheat, subcooling, and...

So, If I install a brand new HeatCraft condensing unit, etc with R-404a, its okay to leave the sight glass flashing?? Isn't R-404a is a blend? If so, then how do I know how much flashing is okay...

[QUOTE]Originally posted by Dowadudda

They go through everything. It's a good course for a guy just getting into supermarkets. But. You know it's all about their stuff to. Nothing wrong with...

You are missing the point. I'm no chemist, but if you do a little research you'll find that if you nuetralize acid with a "base", the by-product formed is water. Every chemical action has a...

I've heard that Acid Away nuetralizes acid and the by-product formed is water. Doesn't sound like a very good idea to me. I just stick with the tried and true-Sporlan HH suction line filter driers.

A Sporlan C charge is fine for this application. If the TEV is internally equalized (and it probably is for such a small load), then all the pressure drop form the high side to low side occurs acoss...

Now I can visualize how this is piped; I think. The manufacturer put the equalized line at the bottom of the coil's collection header (I guess so it can log up with oil and trash) So, the installer...

Its difficult to visualize what you mean by "the bulb is mounted vertically with it". Please describe again.

As far as mounting the bulb before or after the equalizer is concerned there are two...

Typically, there will be something to identify each orifice for use with a specific refrigerant. So, if you know what refrigerant you're going to put in, then you know which orifice to use.

Andy may yet comment, but I think I can handle this one for him. I found the talble showing the inrush and holding amps in Sporlan's bulletin 30-10. Mine shows 1.4 amps holding for the coil in...

Go to Sporlan's web site. Read their bulletin 20-10 when things slow down.

To keep it simple, orifice sizing is critical for good/equal distribution of refrigerant in coils that have more than one circuit. If the orifice is too big, equal distribution may not occur. This...

TB,

The orifice is there to cause pressure drop, which flashes more of the liquid into vapor. This pressure drop is in no way harmful to the performance of the system. At the same time, this...

Those folks are wrong. First, every system with a TEV requires 100% liquid in order for the TEV to provide it's rated capacity, and to have the best chance at delivering it's maximum performance. ...

[QUOTE]Originally posted by lmtd
[B]No, it is NOT acceptable to mount the bulb vertical with the cap tube attached to it pointing down.

I'll probably get flamed for this, but here it goes...

With all due respect,

It is true that the CPR valve is there to protect the compressor. It is also true that it will not protect against slugging.

However, the way it protects the compressor...

I'm with icemeister and frosty-ne. A sight glass is absolutely essential for charging on a TEV system with a reciever whether its a refer system or an AC system.

You can't expect full capacity...

I've been involved with one job so far, and it went fine. You'll have to do you own due diligence though. The compressors are relatively expensive, but very efficient and light weight/compact. ...

Need more info.

Refrig., evap temp., cond. temp. liq. temp., and is a refrigerant distributor used? Does the compressor unload, and if so, down to how many tons? I hope your liquid line isn't...

Drifter,

I would expect your evap pressure to run lower since effectively your evap has lost heat transfer area due to the oil logging. Also, you may or see a lower than normal superheat heat or...

I don't know of any suppliers that make a 1/4" epr. Just to cover the bases though, its best to size an epr based on the normal criteria of refrigerant, tonnage, available pressure drop, etc, and...

ruud-man,

Continue with what? If its about my comment regarding constant superheat, I think a different thread should be started so as to not dilute John Dalton's quest here.

I'm suprised this topic is still being discussed. It would seem old wives tales are slow to die. Andy Schoen, former TEV product manager for Sporlan has already commented about this topic in a...

Dear John,

No apology is required. As I have written to you before, my purpose for posting here is to share my knowledge. You won't see me posting here about the air side of things as that is...

Dear John,

All I can tell you is that you should call Sporlan and hear it from them (636)239-1111 ext. 235. I don't know exactly how much liquid is in a vapor charge (aka a limited liquid...

Regarding the so called "tit", it normally make s no difference where it is relative to the rest of the bulb. I've had this specific conversation with Sporlan's technical people at the factory. ...

[QUOTE]Originally posted by seaboard
[B]I agree with you 100% that too often guys replace the entire valve when replacing the powerhead does the job. Another option on a direct replacement is to...

The first problem is that it's an Alco product-yuck! That junk is made in Mexico. Rip it out and put in a good Sporlan take apart catch-all. How did all that crap get past those Alco rock blocks...

icemeister,

If Copeland's info on this compressor states it can pump -5 f (maximum allowable evaporating temp, then set the cro valve for -5f = 26 psig/404a. Set it , and forget it! What Copeland...

azhogdog,

I'm assuming you mean when the condensing unit(condensor plus compressor)in your questions.

When your condensing unit is significantly undersized compared to the evaps, you can...

It sounds like originally the system needed the desuperheating valves to offset the hot gas going into the suction line. Perhaps for reasons of increasing oil return out of the evap during low load...

Roby,

Thanks for catching my mistake. I left out the part about R-12 and wax.

The pour point of an oil is the lowest temp at which it will flow, or "pour" when tested under certain specified conditions. This is an important consideration in selecting an oil for a low temp...

Dear John Dalton,

The problem with a forum such as this (written word) is that unless a person is a trained journalist, its easy for one's comments to be misinterpeted. Additionally, we aren't...

By the way, I think it's somewhat disengenuous to sign off "Respectfully Submitted" after having taken pot shots.

fridg,

Although the P-H diagram can be used as a tool (and a very good one indeed), I wouldn't recommend it as your first line of trouble shooting.

Given the time, practice, and knowledge of...

Dear John,

A simple answer to this question hasn't cleared up the controversy. Also, a simple answer may not lead to any greater understanding of how things really work.

[QUOTE]Originally posted by airworx
[B]if you have a system which uses a txv what happens is when you overcharge a system the txv will close off which will
drop suction pressure and cuase icing. ...

Thermodynamically the HP required can be calced by:

Mass flow(lbs/hr)x heat of compression (btu/lb) x 2545 btu-hr/HP. All of this at a given set of specific conditions.

To get total hp, you...

Hey cardinal ac,

If the refrigerant distributors used are the kind with removeable orifices, you should proceed with caution. Nozzle type distrbutors can only tolerate half loading before they...

In larger heavy commercial and idustrial type systems, take apart sytle filter driers (shell type)are typically installed with a bypass. The bypass consists of 3 hand valves and the take apart...

keep in mind that Ohm's law only works for resistive loads. If you have an iductive load (motor, solenoid, anything with windings), Ohm's law is not applicable.

I'm not picking on anyone here, so please don't take this personally. Some here have said:

"because an overcharge will put more liquid in evap which causes a lower line temp which will close the...

Goose,

As Lusker said,

"You are going to find that there are just some guys out there that have their own way of doing things. This doesn’t make them right or wrong and in most cases you will...

On the valve plate there was this black substande. Un-identifyable in appearance.

It looked like a mixture of charcoal & black smelly oil.


Anyone got ideas on system clean up?


Sounds...