User Guide

VG60 ELECTRONIC VACUUM GAUGE
Thank you for purchasing our VG60 Vacuum Gauge. It is an accurate instrument with original features. Please read these instructions carefully to
get the best performance and many years of trouble-free service from your VG60.
OPERATING CONTROLS AND FUNCTIONS
1. ON-OFF slide switch.
2. Dual purpose LED indicator.
A. Illuminates when slide switch is ON.
B. Hardly glows, or may not Illuminate when battery is low.
3. LED lamps indicate the entire range for vacuum pump from atmosphere
d
own to 50 microns vacuum.
4. Tough high impact case.
5. Standard 1/4 inch male flare fitting.
6. Quick cap for fitting.
7. Built-in hanger.
8. Tilt up cover for battery compartment.
9. Compartment for 9 volt battery.
10. Calibration screw.
HOW TO USE VG60 ON REFRIGERATION SYSTEMS
The purpose of this introduction is to aid the service engineer in evacuating any system by the most efficient method. The capacity of a vacuum pump
is defined by how fast the pump can evacuate a system; and the efficiency of the pump is defined by how deep a vacuum it is capable of pumping
over a length of time. The level of vacuum you want to achieve can only be determined by a vacuum gauge.
Most service engineers who are experienced in evacuating systems know beforehand the approximate time the vacuum pump will have to run.
However, the only proof he has that the system is actually empty is by the reading of a vacuum gauge.
We have researched the numerous arrangements of using shut off valves and have found the subsequent valve layout to be the most versatile and
efficient. (Fig.2)
The following recommendations will help you pull a vacuum in the shortest possible time:
1. The valves and connecting tubes (Fig.2) that are in-line from the refrigerating unit to
the pump should be of the same ID (size and type) as the original fitting on the
suction side of the pump.
2. Always pull a vacuum simultaneously from the high and low side of the system.
3. If you must connect your hose to an access fitting on the system, first remove the
core.
4. Use the shortest possible length of hose.
Oil vapors from a vacuum pump will contaminate all electronic vacuum gauges.
Oil vapors are produced after the running pump has stopped. The air at
atmospheric pressure rushes into the vacuum side of the pump causing an oil
turbulence. Most pumps are equipped with a check valve, but it only takes a tiny
amount of vapor to affect the electronic sensor. The following simple precautions
will assure you of many years of trouble free service. Referring to (Fig.2):
Before you stop the vacuum pump.
1. Close the pump valve first. 2. Close the vacuum gauge valve.
Before you start the vacuum pump.
1. Close all valves. 2. Start the pump. 3. Open pump valve. 4. Gradually open main
valve, wait 5 seconds before opening gauge valve.
MAINTENANCE
The VG60 electronic vacuum gauge sensor is cleanable. It is good maintenance practice to clean the sensor periodically. Use an eyedropper to pour
about 2 teaspoons of ordinary rubbing alcohol into the fitting. Cap the fitting and shake about 10 seconds; empty and air dry. (The slight movement of
the fitting in the case is normal and does not affect the internal connection in any way.)
When transporting the VG60 as a separate unit, close both ends with the quick caps.
EVACUATING A REFRIGERATION SYSTEM
Emptying a system of all its vapors, including moisture, is a matter of time, and the length of time depends upon:
1. Size of the vacuum pump. 2. Efficiency of the pump. 3. The size of the system. 4. The distance of the furthest part of the system to the pump.
The most common time destroyer is an inefficient vacuum pump or a leak in the system that is discovered after an hour of pump running time. To
prevent both from happening, test for leaks before you start the vacuum pump by closing all the valves except for the pressurizing valve. When you've
completed the leak test and you are removing the test pressure gas, you can test the pump for efficiency by leaving the main valve closed and opening
the pump and vacuum gauge valve. This is called a blank-off test. The vacuum gauge shows the lowest possible vacuum the pump is capable of
pulling. This one time blank-off test does not guarantee that the pump will be that efficient after it gets hot from running more than 15 minutes. There
are many instances where the oil in the pump should be changed, and it becomes obvious only when the pump is running hot.
FIG. 1
FIG. 2
If you estimate, for example, that the vacuum pump should evacuate the system in about 1 hour, it would be a smart plan to periodically che
ck the
pump for efficiency. It only takes a few seconds. After the blank-off test, close the pump valve and open the main valve. The reading on the VG60 tells
you the vacuum level the system is at. Each time you test the system for its vacuum level, there should be a progressive reduction in the micron level. If
the reading remains at the approximately 1,000 micron level, there is either some gas pockets that are being drawn from the oil in the system or
moisture in the system. In either case, if you know that the compressor is efficient and there aren't any leaks in the system, it is going to be a matter of
time to evacuate down to your target level.