Low side liquid charging devices

[surenuff]

By throttling the gauge manifold, I have always just been able to get a feel for how much liquid/gas I am getting into the suction line/service port. I see no need for these devices. But I do know that was designed to be hooked up to the bottle, and the service hose hooked to it. That allows for a lot of flashing to take place before it gets out of the service gauges/hoses.

[jpsmith1cm]

My main concern is when charging directley into the suction service valve on the comp. So the little bit of liquid entering after the restriction device is ok because its a lower pressure liquid and damaging the compressor isnt a big concern. I was just under the impression that you could use the kwic charge, open the low side on the manifold wide open and let er rip without damage to the compressor- but then when it starts to frost up the service valve while charging in a AC app I thought huh.

Next question is 'what type of compressor?'

If it is an air cooled model, then you MUST monitor the charging at all times. I oopsed one of those years ago and never forgot it.

If it is a refrigerant cooled model, you don't have to worry nearly as much. Think about it. Look at a cut-away drawing of the compressor. Those little droplets of liquid must first make it into the machine, through the entire motor and into the head where the valves are in order to cause any damage.

I've seen low temp compressors with massive floodback and a frostline to the valve plate and no damage was ever done to those machines.

They are very tough to damage by improper charging.

[dave1234]

Next question is 'what type of compressor?'

If it is an air cooled model, then you MUST monitor the charging at all times. I oopsed one of those years ago and never forgot it.

If it is a refrigerant cooled model, you don't have to worry nearly as much. Think about it. Look at a cut-away drawing of the compressor. Those little droplets of liquid must first make it into the machine, through the entire motor and into the head where the valves are in order to cause any damage.

I've seen low temp compressors with massive floodback and a frostline to the valve plate and no damage was ever done to those machines.

They are very tough to damage by improper charging.

I see what your saying. And I believe most all recips are suction gas cooled. What do you think is more susceptible to failure do to slugging- a can or semi-hermetic. I know scrolls can handle it well. In fact I went to an Emerson/Copeland seminar in which the rep "challenged" us to wreck a scroll from slugging liquid. Bold statment. See some rotarys in mini-splits and some other stuff. Seen screws but never worked on one.

[jpsmith1cm]

A hermetic, recip compressor is refrigerant cooled.

It's a draw.

Rotarys are a different animal.

[cold spell]

I've seen low temp compressors with massive floodback and a frostline to the valve plate

We call those panda bears round here.

[craig1]

I see what your saying. And I believe most all recips are suction gas cooled. What do you think is more susceptible to failure do to slugging- a can or semi-hermetic. I know scrolls can handle it well. In fact I went to an Emerson/Copeland seminar in which the rep "challenged" us to wreck a scroll from slugging liquid. Bold statment. See some rotarys in mini-splits and some other stuff.

All hermetic recips are refrigerant cooled. Some semi-hermetics are refrigerant cooled, like the Copeland Discus. Some are refrigerant cooled, like the Copeland K and RA series.


Scrolls are pretty much invincible to direct damage from refrigerant. They are still susceptible to oil washout from long term flooding.

Rotaries are EXTREMELY sensitive to floodback. The suction line is piped directly into the compression chamber and the discharge gas goes into the can. Exactly the opposite of a recip or scroll semihermetic. This is why almost all rotaries come with a built in suction accumulator.

[dangpgt97]

We call those panda bears round here.

lmao