Multiquip ST41230, ST61460 Water Tank Storage, Electrical Insulation Testing, Long Term Storage

maintenance

Water Tank Storage

If an installed pump (immersed in water) has not been in operation for a long period of time, check the insulation resistance and run the pump for 30 minutes every month.

If the pump cannot be run due to lack of water in the tank inspect the pump and turn the impeller by hand each month and prior to putting the pump back into service. If insulation drops below 10 megohms, contact an authorized Multiquip service center.

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.

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
￿	UP	GROUND WIRE
￿	K￿ SET
		(GREEN)

MEGGER™

500 VDC INSULATION

TEST METER

What is Insulation Resistance Testing

Insulation resistance testing applies a regulated stabilized high voltage (Figure 19), typically 500 VDC or greater across a dielectric (power cord). Measuring the amount of leakage current flowing 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 flow 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.

A high 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 significant amount of current may be leaking through and along the insulation.

Figure 19. 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 qualified and trained personnel should

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

Long Term Storage

1.Area must be free from excessive humidity, corrosive gases, vapors or vibrations which might damage the pump.

2.Store pump in a vertical position on a pallet or stand.

3.Coil up the cable, and seal the open end (control box wires) with waterproof tape or a cable cap. This will prevent moisture from penetrating into the motor which could cause severe damage to the windings.

4.Give all unpainted surfaces a light coat of oil or grease to prevent corrosion.

5.If new pumps are stored for more than two months, turn the impeller by hand every two months to prevent the mechanical seal faces from seizing up. Failure to do this may result in seal damage when the pump is started.

st4/ST6 series submersible pumps• operation AND PARTS manual — rev. #1 (11/12/13) — page 23