The Steps
- Add core removal assemblies to the system and remove the cores.
- Attach large diameter hoses to the core removal assemblies and run them to the vacuum pump.
- Place micron gauge on the system side, not the pump side, to monitor evacuation performance.
- Start pump and open up core remover ball valves.
Full Answer
How do you use a vacuum gauge on a refrigerator?
Most refrigerant gauges and hoses are designed for charging only, not generally rated for deep vacuum. Presuming the system is still under pressure, dump nitrogen. Connect your valve core removers to system and remove valve cores. Connect your vacuum hoses or copper lines to valve core removers and vacuum pump.
What does it mean to pull a vacuum on the system?
Pulling a vacuum on the system is simply removing matter (mostly air and nitrogen) from inside the system so that the pressure inside drops below atmospheric pressure. We use a vacuum pump specifically designed for this, and we measure the vacuum in the microns of mercury pressure scale (micron) using a vacuum gauge.
How do you remove a core from a vacuum pump?
Attach large diameter hoses to the core removal assemblies and run them to the vacuum pump. Place micron gauge on the system side, not the pump side, to monitor evacuation performance. Start pump and open up core remover ball valves.
How do you turn off a vacuum pump?
Shut off the vacuum pump. When you are satisfied with how long your system held the vacuum, shut the pump off using the same switch mechanism you used to turn it on. Let your vacuum disengage completely before you disconnect the system.
How do you pull a vacuum out of a system?
3:044:35How to Pull a Vacuum on a System - YouTubeYouTubeStart of suggested clipEnd of suggested clipIf you have a gas balance on that make sure that's in good working condition make sure all yourMoreIf you have a gas balance on that make sure that's in good working condition make sure all your lines are open your Schrader's are removed. And you're ready to go ahead and pull your vacuum.
How do you pull a refrigerator vacuum?
2:256:38ApplianceJunk.com - Evacuation & Charging of a Refrigerator - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou must draw a vacuum of 30 inches for 30 minutes to ensure your system is properly vacuumed out orMoreYou must draw a vacuum of 30 inches for 30 minutes to ensure your system is properly vacuumed out or. If you have a micron gage. Simply pull the system down to 500 microns or less.
Can you pull a vacuum on AC system with refrigerant in it?
Using the vacuum pump to pull refrigerants will only damage the pump. They're only designed to evacuate moisture. If you want to pull refrigerant with a vacuum pump, don't do it. Instead, get a refrigerant recovery machine.
Do you pull vacuum from low or high side?
It is crucial to always pull the vacuum from both high and low-side service ports. Then remove the Schrader cores from the service ports during evacuation by using an evacuation service tool core remover. This tool has a valve on it that can be used during the vacuum hold test.
How long should an AC system hold a vacuum?
How Long Should You Pull a Vacuum On a Normal Compressor Change Out? To remove all of the air from your air conditioning system, you should give your vacuum at least 15 minutes and up to 30 to run at its maximum speed while it is functioning.
Why should you pull a vacuum?
The process of pulling vacuum is performed to rid the system of these potentially harmful substances to ensure that the refrigerant in the system has a clean, pure environment in which it can operate best. Not pulling proper vacuum can lead to: Premature corrosion. Line restrictions.
What happens if you don't pull a vacuum on AC system?
KOG. What will happen if you don't evacuate moisture is that the acids formed by high temperature reaction of refrigerant and moisture will destroy the condenser, the evaporator, the compressor and any control valves in the system as well as any aluminum lines. In other words, every part of the entire system.
How long does it take to pull 500 microns?
With less than a thimble of water, you will notice that the evacuation time almost exactly doubled. It took 11 minutes and 46 seconds to hit the 500-micron mark, as removing water is work and takes time. After hitting 500 microns, at isolation, the tank pressure very quickly rises (decay).
Does evacuating an AC system remove the oil?
Does Evacuating a Car AC Remove Oil? While the process of evacuation eliminates moisture, it does not clear the air conditioning system of oil or debris. For the same reason, sludge and deep vacuum methods cannot replace liquid-line or suction line driers. Only proper filtration can remove particulates and sludge.
Can I pull vacuum from low side only?
Yes. You can pull a vacuum from one port. The AC system is a continuous loop. There is a part known as an orifice tube which restricts the flow of refrigerant, but doesn't stop it.
What is a perfect vacuum in HVAC?
491 PSI, or roughly 1/2 of a PSI. The force of the atmosphere around us is equal to 29.92 inches of mercury (Hg) or 14.7 PSIA. Therefore, a perfect vacuum can be thought of as 0 Hg, although a “perfect” vacuum can never be achieved.
When a system is in deep vacuum you should never?
You should never energize the compressor. A hermetic compressor's motor winding could be damaged if energized under a deep vacuum.
Where do you vacuum a fridge?
We'll start with the inside.Clean the inside. ... … or at the front bottom of the appliance, behind a toe grill that snaps easily off.Vacuum the coils using a brush attachment. ... If your refrigerator has a snap-off toe grill, don't forget to thoroughly vacuum the inside of the grill before reattaching it.
How do you vacuum a refrigerator compressor?
0:525:14Refrigerator cleaning coils and compressor ... - YouTubeYouTubeStart of suggested clipEnd of suggested clipYou just need a whatever size this is looks like a quarter inch. Or you can use a flat bladed cometMoreYou just need a whatever size this is looks like a quarter inch. Or you can use a flat bladed comet screwdriver take this back off take the front grille off.
How does a vacuum pump works?
Vacuum pumps essentially move gas molecules from one region to the next to create a vacuum by changing high and low-pressure states. As molecules are removed from the vacuum space, it becomes exponentially harder to remove additional ones, thus increasing the vacuum power required.
How many microns should a vacuum pump pull down to?
with a vacuum pump. Why a Vacuum Pump? ASHRAE recommends evacuation to below 1000 microns for moisture removal and below 500 microns after replacing a compressor. Some equipment manufacturers call for evacuation to 400 microns to ensure that harmful water vapor is removed from the system.
How to get a lower vacuum?
You will need to evacuate system to 500 microns, then break vacuum with dry nitrogen. Dump nitrogen then evacuate down to 500 microns once again, repeat this process one last time after this. The nitrogen helps with dehydrating system.
Where to connect vacuum gauge?
Connect your Vacuum Gauge as far from the vacuum pump as possible, preferably on the system.
What is the rated depth of a vacuum hose?
Vacuum Hoses - Rated to 30 microns or less. Copper lines can be made with copper flare nuts as a cheaper alternative. Most refrigerant gauges and hoses are designed for charging only, not generally rated for deep vacuum.
How many microns should a valve core remover be?
Valve core removers with ball valves - These need to be rated preferably to 30 microns or less. Vacuum Pump Oil. Nitrogen. Presuming the system is still under pressure, dump nitrogen. Connect your valve core removers to system and remove valve cores.
What is the purpose of evacuating a system?
The whole point of evacuating a system is to ensure any non-condensibles and moisture are removed before charging the system with refrigerant. There are two methods to do this and they are the deep vacuum method and the triple vacuum method.
Do you need a vacuum pump for a fridge?
You may need to change oil in vacuum pump, I recommend changing after every use! This is why it is best to have a variety of vacuum pumps as you don't need a 230 litre per min pump on a domestic fridge.
How to test a valve?
Here are a few rule-of-thumb tips: 1 Use a high-accuracy digital gauge with 1.0 or .1 micron resolution down to or below 50 microns. 2 Remove the valve cores with valve core removers rated at less than 30 microns of vacuum. Use the core removers as your blank off valves to keep the hoses out of the system during rise testing. 3 Use two 3/8-in. or ½-in. vacuum rated hoses, or even just one ½-in. vacuum rated hose (depending on the size of the system), from the core remover (s) straight to the vacuum pump. 4 Put your vacuum gauge as far away from the pump as you can possibly get it. The farther away from the pump your vacuum gauge is, the more accurate your measurement of the vacuum in a system will be and the more you will be able to tell about contaminants and leaks in the system during evacuation.
Do service companies sell duct systems?
Your first thought may be, "Service companies don't sell duct systems! Only new construction companies deal with them." If so, think again. Service companies that renovate existing duct systems along with equipment replacement have found an additional source of highly profitable work with little competition.
Does vacuum move in a wave?
Remember, vacuum moves in a wave and seeks its own level, just like pressure above atmospheric level does. We do not see the wave as much as we do with higher pressure, but pressure drops occur through a lineset or a coil, and the lowest pressure in a system during evacuation is at the pump.
What is the easiest way to pull down a refrigeration rack?
DEEP EVACUATION ON A GROCERY STORE RACK: Multiple large hoses coupled directly to a high-cfm pump is the easiest way to pull down a refrigeration rack.
What should be kept out of a refrigerator?
The only things we want inside the system are the proper refrigerant and the correct oil in the factory-designated quantities. Things like air, moisture, dirt, copper shavings, oxides, or anything else that isn’t refrigerant or oil should be kept out.
WHAT EXACTLY IS EVACUATION?
The atmosphere all around us is pressurized to around 14.7 psi (at sea level). Pulling a vacuum on the system is simply removing matter (mostly air and nitrogen) from inside the system so that the pressure inside drops below atmospheric pressure.
Why is a CRT used for vacuum?
This greatly decreases evacuation time because cores restrict the flow from the system toward the negative pressure provided by the vacuum pump. The CRT also acts as a handy place to connect a vacuum gauge, and as an easy method to shut off and isolate the system and micron gauge from the pump and hoses when testing.
What is a vacuum hose?
Vacuum hoses are designed specifically to hold under deep vacuum and to keep moisture and contaminants from bonding to the inside. A typical refrigerant hose used for recovery and charging has been exposed to refrigerant, oil, moisture, and other contaminants.
Why do vacuum hoses off gas?
Hose contamination or off-gassing. If the vacuum hoses have been used with refrigerant, they can contain contaminants or moisture. Some new hoses begin to off-gas when placed under deep vacuum. Refrigerant sensor interference, which can occur if the system previously had refrigerant in it.
What are the problems with vacuum?
The greater challenges that prevent proper vacuum are: 1 Leaks, even very tiny ones. Common culprits are hoses, manifolds, joints, or flare fittings. 2 Vacuum restrictions. Because vacuum occurs at a maximum pressure differential of 14.7 psi, all restrictions can slow down the process. These include small hoses, longer hoses than necessary, valve cores, hose core depressors, manifolds, ¼-inch pump ports, and anything else that inhibits maximum flow. 3 Improper micron gauge placement. 4 Hose contamination or off-gassing. If the vacuum hoses have been used with refrigerant, they can contain contaminants or moisture. Some new hoses begin to off-gas when placed under deep vacuum. 5 Refrigerant sensor interference, which can occur if the system previously had refrigerant in it. The refrigerant can be pulled out of the system as well as released from the oil during evacuation. This can interfere with the micron gauge readings. 6 Technicians who use the “30-minute vacuum, and let it rip” approach instead of proper measurement. 7 A pump that isn’t working properly and will not easily pull below 50 microns when isolated.
What is vacuum pump oil?
Vacuum pump oil, also called sealing oil serves three primary functions: it seals the pump, it lubricates the pump and it cools the pump. The first job of vacuum pump oil is to SEAL.Changing the oil in the vacuum pump after every use is only the starting point.
Can a refrigeration manifold be used for evacuation?
If a technician uses a standard refrigeration manifold for both charging and evacuation, that technician is making a fundamental error. Only vacuum-rated manifolds and hoses should be used for evacuation and, if you are pulling vacuum through the gauge set, that should also be vacuum-rated. It is surprising to realize how many technicians actually believe that a manifold is necessary for pulling a deep vacuum; this simply is not true. Many technicians have been able to get to 500 microns using a pressure manifold with pressure hoses, but it takes longer than necessary to get the job done, and wasted time is wasted money.
How to pull a vacuum pump?
1. Start with fresh oil in your pump, vacuum pump oil has the ability to grab hold of moisture and contaminants. New oil will speed up the evacuation process. When changing vacuum pump oil, it is recommended that you change the oil while its warm, warm oil holds more contaminants than cold oil. ...
Why is it important to pull a vacuum?
Pulling a proper vacuum is vital to the operation and longevity of any refrigeration or cooling system. Moisture and other contaminants that are not removed can wreak havoc on system internals over time and can cause premature failures. Lets go through the steps of pulling a proper vacuum. 1.
What gauge is used to determine when a vacuum has been achieved?
7. The evacuation process is not dependent on time or when your compound gauge hits 29.92” Hg. Use the reading on the micron gau ge to determine when a proper vacuum has been achieved. It is common within the industry to set a vacuum target of 500 microns.
When pulling a vacuum on a system with a solenoid valve, it is highly recommended that the valve?
Note: When pulling a vacuum on a system with a solenoid valve, it is highly recommended that the valve is completely open at all times during the evacuation process. Use the Yellow Jacket Solenoid Valve Magnet to perform this task.
Can you pull a vacuum through a charging manifold?
3. It is recommended not to pull a vacuum through a charging manifold due to many potential leak points. Use a vacuum manifold, such as the Yellow Jacket SuperEvac, and attach it to the 3/8” port on the vacuum pump. 4.
How to get air out of a vacuum?
Open the side gauge valve. Once your vacuum is on, you will need to open the gauge valves, located on the side of each gauge. This allows the vacuum to start pulling air out of the system.
How to turn on vacuum pump?
Start your pump. After you are sure everything has been securely connected, use the switch device on your vacuum pump to turn it on. You should be able to hear the vacuum running once it is switched on.
How to connect a vacuum gauge to a vacuum?
Attach your gauges to the ports. You will need a gauge set that connects to both your vacuum and your pressure ports on your AC system. The blue gauge and hose should connect to the low-pressure service port. The red gauge and hose will connect to the high-pressure port. The yellow hose in the middle should connect your gauges to your vacuum.
What is the yellow hose on a car vacuum?
The yellow hose in the middle should connect your gauges to your vacuum. Make sure the gauges and gauge hoses are connected tightly. Loose seals can compromise your vacuum. In your car, your high-pressure port will generally be physically higher than the low-pressure port.
How long does it take for a vacuum pump to work?
Once the valve is open, let your vacuum run at full speed for 15 to 30 minutes to pull out as much air as it can.
What happens if a vacuum pump doesn't hold?
If it’s not able to hold for that long, you likely have a leak and may need to replace components on your vacuum pump.
How many microns should a vacuum run?
Generally, you want to let your vacuum run for at least long enough to get the measurement below 1,000 microns. If you can, try to get it down to 500 microns.
