New member

Re: Generator lockout

While on the subject of you or don't you LOTO when changing or cleaning spark plugs?


Re: Generator lockout

Personaly I think the starter needs to be mechanicaly isolated. In most of my applications there are pneumatic starters, I always make a point to remove the supply line. This is typicaly nothing more than a JIC fitting.
Cat Dealer

Re: Generator lockout

Another thing to keep in mind is that on generators with EMCP3 controllers, it is possible to reset shutdowns and set the control switch to auto or run via SCADA without any physical access to the genset.
New member JC
New member

Re: Generator lockout

Tech1 provides a good simple process. However, please remember that lockout is specifically defined as an action that someone without a key cannot undo. And tagout should go along with it. Energizing the battery charger and releasing the emergency stop are easy enough to undo for someone else without thinking too much about why they were de-energized and pressed to begin with.



LOCKOUT = only the person who locked it can unlock it

TAGOUT = all others can see who locked it and why



New member

Re: Generator lockout

The best way to lock a generator depend on three major factors

a) Type of maintenance needed carried out.

b) Type of starter (i.e. Is it electrical or pneumatic starter)

c) Type of start up configuration (i.e. Is it manual start/Auto local  or  Auto dead buss configured from remote)

When this has being achieved the following points of isolations could be done:


1. Isolate starter motor power or isolate power source to control panel and lockout.

2. Isolate start air or gas supply valve to starter motor and lockout.

3. Isolate fuel gas supply valve to engine and lockout

4. Isolate generator main power breaker at generator skid and switch room and lockout with a safety padlock

Note: Padlocks for Isolations must be secured according to the electrical safety rules governing the said generator.


Re: Generator lockout

We also lockout the fuel supply and PT if there is one for the unit.


Four total as a minimum

1) Unit breaker

2) PT

3) Fuel valve

4) Battery disconnect


Also the other auxiliaries as mentioned, block heater, pan heater.  Also air supply valve if there is an air start.


Lloyd Sawatzky
Electrical Technologist, Team Leader
(work for a utility)

Re: Generator lockout

Tech1... thanks for the additional things to consider.  Do appreciate the help!

Re: Generator lockout

Tom... that helps a lot!  Thanks!

Re: Generator lockout

Typically I will de-energize the batt charger, desconnect the battery, depress the emergency stop and open the main breaker. If I am draining the coolant I also de-energize the block heater (if you don't the heater burns out). if you are familiar with you generator controls, there is also the option of removing one of the remote start leads.
New member

Re: Generator lockout

I think Tom makes a good point.  If it's got power going to the gen set, it needs to be turned off and locked off.  I think OHSA has some "fancy" wording for it, but that is their intent.




Larry Louree
Florida Registered Electrical Contractor
Apopka, Florida