Troubleshooting of Cummins EFC Governor

Operation

Governing Mode

Isochronous to 5% droop

Steady State Stability

±1/4%

Operating Input Frequency Range

1K to 5K Hz

Idle Frequency Range

200 to 2200 Hz

Response Time of Actuator

15 milliseconds

Power

Operating Voltage

12 Volts D.C. ±3 Volts or 24 Volts D.C.±6 Volts Continuous

Ground Polarity

Negative ground (case isolated)

Power Consumption (Maximum)

94 Watts (12 or 24 Volts D.C.)

Nominal Operating Current

1.3 amps at 24 volts

Nominal Operating Current

2.6 amps at 12 volts

Maximum Operating Current

3.9 amps at 24 volts

Maximum Operating Current

7.8 amps at 12 volts

Environmental

Ambient Operating Temp.

-40℃ to 185°F [-40℃ to 85℃]

Maximum Temp. Drift

±1@ - 40℃ to 185°F[- 40℃ to 85℃]

Relative Humidity

0 to 100% non Condensing

Physical-Remote Control

Dimensions

5.75 in. x 4.44 in. x 2.15 in. (146mm x 113mm x 55mm)

Weight

2 lbs. [.9 kg]

Mounting

Any position, typically in enclosure

Case Material

Die cast aluminum

Panel Mounted Control

Dimensions

5.5 in. x 4.1 in. x 1.3 in. (140mm x104mm x 33mm)

Weight

1 lb. [.45 kg]

Mounting

16 pin plug-in receptacle

Protection Features

High voltage protection (15 VDC for 12 volts or 32 VDC for 24 volts continuous)

Reverse of supply polarity

Surge protection (80 VDC, 10 msec transient)

Vibration Protection:

(Remote Control) Entire printed circuit board sealed with Silicone filled Epoxy.

(Panel Mounted Control) Circuit board sealed with Silicone Epoxy.

Magnetic Pickup Specifications

Thread Size

5/8 - 18 UNF-2A

Tap Drill Size

37/64 inch

Proximity to Gear Teeth

.028 in. min, - .042 in. max. (Approximately 1/2 to 3/4 turn)

Temperature Range

-67° to 220°F [- 55° to 105°C]

Output at Cranking Speed

1.5 volts AC minimum

Maximum Output

30 volts AC

Coil Resistance

300 ohms maximum

Resistance

5K Ohms ±5%

Linearity

.25%

Travel

360° x 10

Power Rating

2 Watts @160°F [70°C]

Insulation Rating

1000 M Ohms @ 500 VDC

Dielectric Strength

100 V RMS

Operating Temperature Range

+220°F to - 67°F [+105°C to - 55°C]

Wiper Resistor - For the Remote Mounted Control Fine Speed Adjustment Potentiometer

120K Ohms, 1/4 Watt

100 PPM Temperature Coefficient or Less Metal Film

Resistance Test of Actuator Coil

When the actuator leads are disconnected, the coil resistance must be 6.8 to 7.6 ohms for the 24 volt model or 2.0 to 2.3 ohms for the 12 volt model.

Table 1: Normally Open Electric Fuel Control Governor Parts

Part No.

Description

3052504

Actuator Low Flow-24V-For use on NT-855 and KTA-19 (KTA-1150) engines

3052505

Actuator High Flow-24V-For use on VTA-28 (VTA-1710), KTA-38 (KT(A) 2300) and KTA-50 (KTA-3067) engines

3052506

Actuator Ultra High Flow-24V-For use on KTTA-38 (KTTA-2300) and KTTA-50 (KTTA-3067) engines

3052507

Actuator Low Flow-12V-For use on NT-855 and KTA-19 (KTA-1150) engines

3052508

Actuator High Flow-12V-For use on VTA-28 (VTA-1710), KTA-38 (KT(A)-2300) and KTA-50 (KTA-3067) 

3052509

Actuator Ultra High Flow 12V-For use on KTTA-38 (KTTA-50(KTTA-3067) engines

3037359

Control-12 or 24V (For Remote Mounting, Enclosed)

3032733

Control-12 or 24V (Plug-In type, for mounting in Cummins Engine Panel or Generator Control Panel Enclosure

Table 2: Normally Closed Electric Fuel Control Governor Parts

Part No.

Description

3044189

Actuator, 24V, Normally Closed, Low Flow, for use on NT-855 and KTA-19 engines

3044190

Actuator, 24V, Normally Closed, High Flow, for use on VTA-28, KT(A)38, and KTA-50

3044191

Actuator, 24V, Normally Closed, Ultra-Hi Flow, for use on KTTA-38 and KTTA-50

3044192

Actuator, 12V, Normally Closed, Low Flow, for use on NT-855 and KTA-19 engines

3044193

Actuator, 12V, Normally Closed, High Flow, for use on VTA-28, KT(A)-38, and KTA-50

3044194

Actuator, 12V, Normally Closed, Ultra-Hi Flow, for use on KTTA-38 and KTTA-50

3044195

Control-12 or 24V, Plug-In-Type, for mounting in Cummins Engine Panel or Generator Control Panel Enclosure

3044196

Control 12 or 24V, Remote Mounting, Enclosed

Table 3: Parts Common for Both Systems

Part No.

Description

3034572

Magnetic Pickup (For SAE #1 or #0 Flywheel Hsg. with engine wiring)

3034573

Magnetic Pickup (For SAE #00 Flywheel Hsg. with engine wiring)

3015105

Remote Speed Potentiometer (See Remote Control)

104215

Idle-Run Toggle Switch

213272

Magnetic Pickup (For SAE #1 or #0 Flywheel Hsg. without engine wiring)

3003916

Magnetic Pickup (For SAE #00 Flywheel# Hsg. without engine wiring)

213273

Wiring Harness for 213272 and 3003916 magnetic pickups

Table 4: Actuator Mounting Parts for an AFC Housing

Part No. 

Description

193734

O-ring. Plug

145504

O-ring, Actuator

145505

O-ring, Actuator

3029854

3029853

Gasket

Spring, Return (Qty. 2)

3029300

Plug, O-ring

3017051

Capscrews, 1 1/4 inch (Qty. 3)

Table 5: Actuator Mounting Parts for an EFC Housing

Part No.

Description

3008248

O-ring, Shaft (Qty. 2)

3029853

Spring, Return (Qty. 2)

3048182

O-ring, Flange

3017051

Capscrews, 1 1/4 inch (Qty. 3)

Cause

Correction

No Fuel in Tank or Tank Valve Closed

Add fuel to tank or open tank valve.

No Fuel Cylinder Head

Loosen fuel line at cylinder head while cranking engine. Check fuel line check   valves.

No Fuel Through Shutoff Valve

Manually open shutoff valve.

Shutoff Valve Electric Circuit

Check voltage from off/on switch, Reset circuit breaker. Reset over-speed stop switch. Check safety controls. Check shutoff valve coil voltage. Check wiring.

No Fuel to Shutoff Valve

Loosen pipe plug in shutoff valve and crank engine.

No Fuel Through Normally Closed Actuator

Check for power to the actuator. Check for power in and out of the control.

Normally Open Actuator Normally Closed Control

Change actuator or control

Normally Closed Actuator Normally Open Control No Magnetic Pickup Signal

Identify cause of magnetic pickup signal loss and correct. Change actuator or control.

Symptom: Engine Has Rough Performance Or Surge

Cause

Correction

Air in Fuel

Install sight glass and check for air in fuel.

Control Adjusted Incorrectly

Follow adjustment procedure. Reduce gain.

Actuator Sticking

Loosen all three capscrews and tighten again per procedure.

Actuator Return Springs Broken or Missing

Remove actuator and install new springs.

Actuator O-rings Defective

Remove Actuator and Replace O-rings.

Actuator (Normally Open)

Remove EFC control leads to actuator. Connect battery to actuator. Start engine. If engine operates at high idle, replace actuator.

Actuator (Normally Closed) Defective

Remove EFC control leads to actuator. Connect battery to actuator. Start engine. If engine operates at low idle, replace actuator.

Fuel Pump Housing Defective

Replace fuel pump housing.

System Voltage Below 19V for 24V System or 9.5V for 12V System

Charge batteries.

Battery Charger Not Connected Direct to Batteries

Connect battery charger directly to battery terminals.

Cause

Correction

Voltage Above 8V at Actuator on 12 Volt System or 16 Volts on 24 Volt System

Repair fuel pump. Replace actuator

Voltage Above 8V at Control Outlet to Actuator on 12V System or 16V on 24V System

Check wiring and connections

Voltage Not Available at EFC Control

Check wiring and connections. Check battery voltage.

AFC No Air Needle Valve Loose or Not Installed

Tighten valve or replace AFC no air plug with needle valve.

Magnetic Pickup Voltage Below 1.5 VAC when Operating Engine

Check terminals 13 and 14 on the printed circuit board inside the engine mounted instrument panel or terminals 5 and 6 on the remote mounted control for   magnetic pickup voltage.

EFC Control Failure

Replace EFC control

Incorrect Normally Closed Control Installed and No Magnetic Pickup Signal

Identity cause of loss of magnetic pickup signal and correct. Install normally open control.

Symptom: Engine Operates At High Idle – Normally Closed Acutator

Cause

Correction

Wrong Controller (Normally Open Controller on Normally Closed Actuator)

Verify that you have a Normally Closed Controller.

Voltage Above 19-20V on Controller Actuator Output (9-10V on 12V Systems)

Check wiring. If wiring is okay, replace controller.

Voltage Above 19 20V on Actuator (9-10V on 12V Systems)

Check wiring. Replace actuator if necessary.

O-rings Detective on Actuator Shaft

Remove and inspect Replace O-rings if necessary.

Symptom: Engine Has Low Power - Normally Open Actuator

Cause

Correction

Engine Fuel Pressure Below the Specifications

Adjust to the specification. Check the fuel pump calibration.

Fuel Restriction Between Fuel Pump and Cylinder Head

Correct the restriction.

Injector Flow Not Adjusted Correctly

Check the injector flow.

Symptom: Engine Has Low Power - Normally Closed Actuator

Control Output Below 19-20V (9-10V on 12V Systems)

Replace Controller

Fuel Pump Calibration Not Correct

Remove and calibrate fuel pump

Fuel System Problem

Refer to fuel system manual.

Symptom: Engine Operates Below Idle Speed

Cause

Correction

Idle or Run Potentiometer Not Adjusted Correctly

Check the adjustment procedure.