The function of the Type ML Governor is to automatically control the operation of either stationary or railway motor-driven air compressors in order to maintain air pressure in a storage reservoir between predetermined limits.

This governor is essentially a single-pole switch of the contractor type, operated by means of a rubber diaphragm, a piston, and a set of levers. The operating mechanism is simple, compact and reliable. The construction of this governor is such that air does not pass through, or come in contact with the operating mechanism, but is restricted to a chamber below the diaphragm, hence troubles resulting from moisture due to condensation are eliminated.

The above governor information comes from General Electric bulletin No. 44590 published in Jan. 1914. Many of you readers will have a copy of this document in your file, for those of you who do not please send for a copy (Form A). Over the last 100 years there have been a few changes to components of this durable governor and a few safety bulletins have been published. A critical concern was the habit of some mechanics to put lubricating oil on parts of the moving sections of the Governor which included the insulators. At 600 VDC the insulation with oil on it will fail and short to ground. DO NOT LUBRICATE ANY INSULATION OR ALLOW OIL IN GENERAL ON THE ML GOVERNORS ELECTRICAL SECTION.

Permanent improvements to the ML Governor include fiberglass construction of the arc chute, assembly insulator base, and fiberglass sheet insulator (1/8″ x 4″ x 4″), behind the blow out coil assembly. A green fiberglass insulator in the moveable portion (aka waterfall) and a dark grey fiberglass bolt for assembly of the moveable portion (aka waterfall). All of these parts are illustrated with photographs and part numbers and all of these parts are available in stock in small quantities up to 10.

Moveable Contact Finger Assembly

Electrical Unit Parts:

Arc Chute Insulator Top / GE serial #138357
Price: $128.00

Insulator Base / GE serial #141221
Price: $181.82

1/8″ x 4″ x 4″ Insulator Base Backing Plate / GE Serial #141222
Price: $15.00

Lower Coil Terminal / GE Serial #47187
Price: $33.95

Blowout Coil with Copper Tabs for Mounting / GE Serial #47185
Price: $145.15

1/4″ ID Fiber Insulator / GE Serial #47194
Price: $3.00

Iron Core Bolt for Blow Out Coil / GE Serial #141402
Price: $5.25

Insulator with 2 steel plates / GE Serial #141219
Price: $44.10

Machine Screws #14-24 x 1/2″ (2 required) / GE Serial #2028
Price: $6.90
#14-24 fits all segments in K controllers and ML Gov*

Top Safety, Pressure Clip, Brass, for Moveable Arm Assembly / GE Serial #47180
Price: $7.10

Small brass clip on bottom of waterfall to reinforce brass receiver casting

Waterfall (moveable) brass without attachments

ML Brass Non-moveable Base (receiver for non-moveable Copper Burn Tip)

Top Safety, Pressure Clip, Brass, for Moveable Arm Assembly / GE Serial #47180
Price: $7.10

GE #138356 piston rests under the large spring* Price: $205.31

Lever intermediate (Yolk for Contact Finger) / GE Serial #14197
Price: $50.44

Operating lever (eccentric complete) / GE Serial #141199
Price: $153.00

2 springs for eccentric assembly / GE Serial #138354
Price: $15.00

Top: Large (big) spring adjustment bolts (long). Usually used with 40/60 psi spring.
Bottom: Large (big) spring adjustment bolts (short). Usually used with 60/80 psi spring

Rubber Diaphragm / GE Serial #138355
Price: $16.25

Spring 65-100/10 high pressure range / GE Serial #47163
Price: $110.00

Spring 40-60 low pressure range / GE Serial #47163
Price: $110.00

GE #138356 piston rests under the large spring* Price: $205.31

COVER PARTS SECTION

Cover / GE Serial #141186
Price: $131.00

Lid Latch with pin / GE Serial #141187
Price: $19.10

Cover Latch Spring / GE Serial #141189
Price: $17.55

Pivot Pin for Cover / GE Serial #141190
Price: $6.00

Waterfall Set Up:

Brass Cup Electrical Connector new 2021, GE Serial #141401. New Part for better electrical connection after replacing steel bolt with fiberglass bolt. Sept. 2021
Price: $7.40

Upper Coil Brass Fixed Base with Burn Tip / GE Serial #47188
Price: $63.25

Moveable Contact Finger Assembled Moveable Arm Assembly (Waterfall) / GE Serial #47177
Price: $160.00

Brass receiver for waterfall moveable copper burn tip. GE # TBA   Price $coming soon