Electrical Insulation Testing

Why perform electrical insulation testing?

Electrical insulation starts to age as soon as it is made. Harsh environments, especially those with extreme temperature changes and/or chemical contamination, cause further deterioration of the insulation (power cord).

As a result, personnel safety (electrocution/shock) and power reliability can suffer resulting in higher operating cost and maintenance.

What is Insulation Resistance Testing

Insulation resistance testing applies a regulated stabilized high voltage (Figure 20), typically 500 VDC or greater across a dielectric (power cord). Measuring the amount of leakage current ﬂ owing through the dielectric will yield a resistive measurement in megohms.

Insulating Material Testing

To verify the integrity of the pump's insulating material (power cable) it will be necessary to perform an electrical insulation test. Any electrical insulation must have the opposite characteristic as the conductor: it should resist the ﬂ ow of current, keeping it within the conductor.

To measure the IR (current x resistance), the use of an IR tester must be employed.This IR tester is a portable device that is a resistance meter (ohmmeter) with a built in DC generator that develops a high DC voltage.

The high DC voltage from the IR tester is usually 500 VDC or more.This voltage, when applied causes a small current to ﬂow through and over the insulation's surfaces.The tester provides a direct reading of IR in megohms.

Ahigh resistance reading would indicate a "good" insulation, meaning very little current is escaping through the insulation. While a relatively low resistance reading would indicate a poor insulation, meaning a signiﬁ cant amount of current may be leaking through and along the insulation.

MAINTENANCE

NOTICE

Insulation resistance is moisture and temperature sensitive. When temperature increases, insulation resistance decreases, and vice versa.

When performing this test measurement, perform the test using the same test parameters as used in the initial testing. Contact an authorized Multiquip service center if the measured cable insulation is 10 megohms or less.

20M	POWER CABLE
	INSULATION
M
V
OFF

K SET	GROUND WIRE
UP

	(GREEN)
	(GREEN)
MEGGER™
500 VDC INSULATION
TEST METER

SUBMERSIBLE

PUMP

Figure 20. Insulation Tester Application

DANGER

Read and follow the manufacturer's user's manual prior to operating insulation tester (megaohm meter). This meter generates a test voltage of 500 volts or greater. Only qualiﬁ ed and trained personnel should

use this equipment. The possibility exists of severe electrical shock, electrocution even death, when using insulation tester.

PAGE 24 — ST4125G/ST6125G SUBMERSIBLE PUMP • OPERATION MANUAL — REV. #0 (11/18/10)

ST6125G, ST4125G specifications

The Multiquip ST4125G and ST6125G are versatile and robust generators that cater to a variety of demanding applications in the construction, rental, and industrial sectors. These portable generators are designed to deliver reliable power with user-friendly features that make them ideal for both professional and recreational use.

One of the standout features of the ST4125G and ST6125G models is their impressive power output. The ST4125G is capable of providing up to 4,000 watts of continuous power, while the ST6125G offers a higher capacity of 6,000 watts. This flexibility allows users to choose the model that best suits their needs, whether for powering tools on a job site or serving as backup power during an outage.

Both models are equipped with a rugged 4-stroke gasoline engine that ensures efficient performance and longevity. The engines are designed with thermal protection to prevent overheating, allowing for extended run times without interruption. Additionally, Multiquip has engineered these generators to have low noise levels while operating, making them suitable for use in residential areas and noise-sensitive environments.

The ST4125G and ST6125G come with a variety of outlets to accommodate different power needs, including 120V and 240V outlets. This versatility makes them ideal for powering everything from small hand tools to larger machinery. Furthermore, the generators feature a dual circuit breaker system for added safety, ensuring a reliable and secure power source.

Portability is another major advantage of the Multiquip ST4125G and ST6125G. Both models are designed with a steel frame and feature large wheels and a folding handle, making transport to and from job sites effortless. The compact design also allows for easy storage when not in use.

In terms of maintenance, Multiquip has incorporated user-friendly features that simplify routine checks and servicing. The generators feature easy access to critical components, allowing users to perform maintenance tasks efficiently.

With their combination of power, portability, and user-friendly features, the Multiquip ST4125G and ST6125G generators stand out in the competitive landscape of portable power solutions. Whether for construction projects, outdoor events, or emergency backup, these generators are reliable choices that meet the demands of various users.