It sounds like
a faulty expansion block as it's common for the low side to go into vacuum when it fails
. It's unusual for the 10PA series Denso compressors to shed debris into the system so once you pull the drier and expansion, check the lines for any sign for debris.
What does pulling a vacuum on AC do?
Pulling vacuum is the
process of evacuating a refrigeration or air conditioning system
(including refrigerant lines, coils, etc) of all unwanted contaminants and particulate primarily dirt, water and air.
Can you pull a vacuum on a compressor?
Some techs say that pulling a vacuum
below 250 microns can damage the compressor oil
. I've done extensive research and spoken to many experts and have seen no evidence that evacuation below 250 microns causes any issues with POE or mineral oil.
What causes negative suction pressure?
The negative gauge pressure number only signifies that
the pressure at the pump suction is less than atmospheric pressure
. As Ankur mentioned, air ingress can be a problem since the pump suction operates below atmospheric pressure.
Why is my compressor pulling low amps?
Low Amp Draw — Low amp draw is caused
by the reduced refrigerant flow rate through the compressor
. During the compression stroke, some of the refrigerant will leak through the suction valve and back into the suction line, which reduces the refrigerant flow.
How long does it take to pull a vacuum on an AC unit?
With a vacuum pump connected to both, low and high air conditioning system sides pull a deep vacuum for
at least 5-45 minutes
. A vacuum of about 500 microns or 29.92 hg gauge pressure is needed for removing any moisture that may have entered the system along with the non-condensable gases while it was open.
Can a vacuum leak cause AC to not work?
3. Automatic or manual control system. If your air conditioning system is automatic, that can be the source of a problem. However, manual systems run off of vacuum, and if you have a
vacuum leak then your system will not operate correctly
.
Does pulling a vacuum remove water?
In other words, a vacuum has less than atmospheric pressure. A vacuum pump
removes air and moisture from the system
before the system is damaged. The deeper and more complete the vacuum, the more moisture is removed, and the likelihood of system complications caused by unwanted water or other contaminants is reduced.
Does pulling a vacuum on AC remove oil?
there will remain a certain amount in low spots of your condenser, drier and evaporator. Pulling a Vacuum on the system (especially for just 30 minutes)
will not remove much (if any) of that oil
…and only then…if it had absorbed moisture.
How long should you pull a vacuum on a normal compressor change out?
The time allowed for decay depends upon the size of the system, but generally,
10 minutes minimum with 1 minute added per ton
is a good guideline. The moral of the story is this: A proper evacuation may take 15 minutes, 15 hours, or 15 days, it simply takes what it takes.
What can cause a lower than normal suction pressure?
- Impurities in diaphragm or piston.
- Evaporator iced up, defrosting faulty.
- Freezing or ice in brine cooler.
- Insufficient liquid subcooling.
- Expansion valve blocked with ice, wax or other impurities.
- Pressure drop in evaporator and/or suction line too large.
What is negative suction head of a pump?
Distance of the liquid source above or below the pump inlet, measured in feet: can be positive OR negative. Positive suction head occurs when the top of the water source is above the suction Inlet of the pump. Negative elevation refers
to suction lift
(like from a pond, tank lower than the pump, etc.)
What causes high suction and low head pressure?
The main reasons your compressor will have simultaneously low head pressure and high suction pressure is due to:
Bad or leaky compressor valves
.
Worn compressor piston rings
.
Leaky oil separator return line
.
Why would a compressor pull high amps?
The overloading could be a mechanical problem, like worn bearings, worn rods, etc. If we were looking at a single-phase compressor, the high amperage could be caused by
a bad run capacitor
. … Note that the compressor should be drawing 57 amps.
What causes a compressor to over amp?
High running amps could mean a bad compressor. But there are other causes which include;
overcharged system, bad/weak capacitor, low line voltage
, or dirty condenser coils. Everything else needs to be checked before the compressor is condemned. Also, these conditions left uncorrected will shorten compressor life.
