Power Generation: Tier 4, EU Stage III, Regulations, Safety

[ChadD]

What's the best method to lock out a generator set for maintenance purposes? 

[Tom · Accepted solution]

Lockout requirements depend on the type of service activity being performed on the gen set.  The typical minimum lockout points would include the following:

1. Battery disconnect (to prevent engine from being started)
2. Generator main breaker or downstream disconnect (although the gen set is usually connected to an ATS, the ATS can't be considered a LO point)

Depending on the configuration, the following additional lockout points might need to be considered:

1. Heaters (likely to be fed from normal power source)
2. control and or monitoring power (that control starting relay)

Hope this helps!

[larrylouree]

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.

[Tech1]

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.

[ChadD]

Tom... that helps a lot!  Thanks!

[ChadD]

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

[Lloydsaw]

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.

[sam_ovedje]

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.

[JC]

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.

Remember:

LOCKOUT = only the person who locked it can unlock it

TAGOUT = all others can see who locked it and why

-jc

[b020mrs]

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.