Multiquip Portable Generator DCA300SSJU4F3

NOTICE: Be sure you have adjusted the engine crank disconnect potentiometer first.

Turn the engine overspeed adjustment potentiometer (Figure 56C) 30 turns clockwise

Using a small, flat-blade screwdriver, set the DIP switch at position 5 (Figure 56D) to the ON position (up)

Start the engine. It should crank and start. Verify that the engine running LED is lit.

Now start turning the overspeed adjustment potentiometer counterclockwise until the engine control shuts down the engine (overspeed fault)

Again using a small, flat-blade screwdriver, set the DIP switch at position 5 to the OFF position (down)

If the overcrank and overspeed LEDs light at the same time on the ECU, reference troubleshooting flow charts in this service manual for additional information.

Sign off on the engine overspeed adjustment

Loosen the jam nut that secures the MPU to the sensor plate

Visually view the flywheel teeth through the hole opening on the sensor plate

Attach a ratchet to the crankshaft pulley and rotate the flywheel gear until the highest point of the flywheel gear tooth is visible

Reinstall the MPU sensor back into the sensor plate. Continue screwing the MPU sensor clockwise until contact is made with the flywheel gear tooth

After making contact with the flywheel gear tooth, unscrew the MPU sensor counterclockwise 1/2 turn

Verify that the MPU sensor does not make contact with the flywheel by rotating the flywheel gear completely around. Flywheel should rotate freely

The MPU sensor-flywheel gear gap should be adjusted so that the minimum voltage required is attained while the engine is in crank status. The voltage setting we are looking to obtain is 2.25 VAC +/- 0.50 VAC

Once the correct gap is obtained, tighten the MPU sensor jam nut to secure it to the sensor plate

NOTICE: Before performing the resistance test, the two black lead wires (Figure 36) must be disconnected from the rotating rectifier.

The main field (Figure 36) consists of two black lead wires with no wire designation. These two wire leads are connected to the DC positive and DC negative terminals on the rotating rectifier in conjunction with the surge protector.

Have the two black lead wires been disconnected from the rotating rectifier?

Upload a photo of the disconnected wires

Using a multimeter (Figure 36), enter the resistance across each black wire as referenced in Table 6, column B.

Does the multimeter reading indicate an open circuit?

If the reading indicates an open circuit, describe the component that may have to be replaced or repaired.

Sign off on the Main Field Resistance Test

Warning: This procedure requires trained personnel with PPE!

If fuel pump relay did not test normal, report the issue to the maintenance team and stop the procedure

Is the relay base holder a 'sealed type'?

If the relay base holder is a 'sealed type', report the issue to the maintenance team and stop the procedure

Cleaning of the relay base holder

Fuel pump relay removed from its base holder?

Dielectric cleaner sprayed onto the contact pins on the relay base holder?

Enter the air pressure used to blow off any dirt and debris

Cable ends, wire connectors and terminals, tighten and repair as needed

Generator end for signs of heat discoloration

Panel controls and breakers for signs of heat discoloration and that they are securely mounted

All gauges for proper operation during test run

Frequency and voltage, adjust as necessary

Sign off on the generator inspection