Fieldpiece SMG5 – Digital Megohmmeter

• Backlit LCD display
• Auto-off to extend battery life
• 1000VDC stresses insulation to measure up to 2000Mohms

The Fieldpiece Digital Megohm Meter, model SMG5, is a compact standalone meter designed for checking HVAC compressor insulation. The SMG5 provides a 1000V voltage source, monitors current, and displays the resistance between the test points. The maximum current output is <1mA. It can be used to determine the condition of insulation from winding to ground in a motor, compressor, or transformer. Includes a case, alligator clip lead tips and leads with removable tips.

The SMG5 Megohmmeter is for fast, easy, and safe testing of insulation resistance. It provides a 1000V voltage source, monitors current, and displays the resistance between the test points. The maximum current output is <1mA. To extend battery life, it automatically turns itself off in 15 seconds.

How Does it Work?

Disconnect the windings and measure the resistance between the windings and ground through the insulation. Determine what a “good” reading is by comparing your reading to values supplied by the manufacturer of the equipment or from your own experience.

Noticing decreasing insulation resistance levels can forecast problems before catastrophic failure.

Why a Digital Multimeter (DMM) Often Isn’t Enough

To test resistance, a DMM supplies low voltage (<1V) to the test points and is capable of delivering only a few milliamps. It’s not a high enough voltage to detect high resistance problems that might indicate moisture and other contaminants and it’s not enough current to measure lower values of resistance.

For your safety:

• Connect the E terminal to the ground using the alligator clip (included).
• Use one hand to conduct the test.
• Make sure to turn meter OFF to avoid accidentally pressing MEAS and creating a 1000V voltage source. If the switch is ON and MEAS is depressed, 1000V will appear on the terminals.

Competitive Advantages

The Fieldpiece Megohm Meter, model SMG5, is in a class of its own. It’s affordable and was designed with your safety in mind. When used properly, detachable lead tips and probes along with and alligator lead tip allow for one-handed testing. The compact, slim shape allows for easier testing as well. Auto power off (APO) conserves battery life.

Applications

The SMG5 can be used to determine the condition of insulation from winding to ground in a motor, compressor, or transformer. Disconnect the windings and measure the resistance between the windings and ground through the insulation. Determine what a “good” reading is by comparing your reading to values supplied by the manufacturer of the equipment or from your own experience. Make sure that all measurements are compared to readings at the same temperature. Insulation resistance can vary dramatically with temperature.