Kohler MPAC 1200 / MPAC 1500 — Millivolt Drop Test Procedure

Maintenance · Main power contacts

For the Kohler MPAC 1200 / MPAC 1500, from the Kohler service manual.

Browse Kohler generators & specs →

Before you start

Testing live electrical circuits. Have trained and qualified personnel take diagnostic measurements of live circuits.

Procedure

Apply a balanced load of at least 10% of the switch rating.
Measure the voltage on each phase of both sources from source lug to load lug.
Use an ammeter to measure current flow through the circuit.
Calculate contact resistance using the formula R = V divided by I.
Compare calculated resistance to the maximum contact resistance table.
If resistance is 2 times larger or more, disconnect power, check connections and lug torques, and repeat the test; replace contact if still high.

Tools required

Digital voltmeter Amazon
Ammeter Amazon

Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.

Specs & values

30-200 Amazon eBay A: 0.250 milliohms
225-400 A: 0.200 milliohms
600-800 Amazon eBay FridayParts $29.99 A: 0.175 milliohms
1000-1200 Amazon eBay A: 0.085 milliohms
1600-3000 A: 0.050 milliohms

Source: Kohler service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.

More Kohler repair guides →