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Im wondering who has a Emergency Power Unit for their Aerial Device and if they train members to use it? Im more of an Engine guy however being a small combination department I need to know as much as possible.


Our department has a 75 Pierce Heavy Duty Ladder. This truck came with a EPU switch to be used for the outriggers as well as the Aerial device. So some of the questions I have.

  1. Do you run this switch with the truck running?
  2. Do you train your Operators / firefighters on the use of it and if so do you have them check it during inspections. 


W Benner

Views: 6822

Replies to This Discussion

Thanks Doug,

This does help..

KTF Brother

Wayne B

Douglas B. Watson said:


During our aerial ops class, we explain what the EPU is and demonstrate how to use it.  I would suggest following the manufacturer's recommendations on how to use it, I'm sure there are differences between manufacturers.

With only the battery switch on, we demonstrate by lowering the boom. The manufacturer recommends it only run for a maximum of 10-minutes and should be used only for lowering or getting the aerial away from a dangerous area.

We don't require the EPU to be checked as part of daily/weekly/monthly maintenance.

Hope this helps, Doug

Yes the emergency hydraulic pump is included in our Aerial Evolutions that we received from Albuqurque NM.  We train to know what it is and how to operate it.  We do not operate it because it is not designed to work for a long period of time.  I believe it is 10 seconds a minute.

We have a 1993 Pierce aerial platform (tower ladder).  The EPU is an electrica motor pump.  Pierce states to run it no logner than 7 minutes and when that is reached to allow it to rest for 30 minutes before using again.  Any EPU should be able to run without the vehicle's diesel motor running; that's its job - to power the aerial if the PTO fails.  Also, on our Pierce it is the same pump used by the EPU that runs the platform leveling switch in our cab.

EPU's are designed to be used in the event that there is a systems failure affecting the aerial device, either in the hydraulics system itself or the power source for your hydraulics (PTO driven/electric motor driven). Either way the EPU draws straight from the battery and can be operated without the truck running. The battery switch may or may not need to be on depending on how the EPU is wired but the engine does not need to be running.

Training any and all persons operating an aerial on the function & use of the EPU should be mandatory and anyone assigned to an aerial should also be familiar w/ it's function and use in the event that the Driver is unable to operate it when it is needed.

The EPU should be checked weekly to ensure it is functioning properly. Waiting until you need it is not the time to find out it's not working or how to operate it. This also keeps it fresh in your mind on how to operate it so that it's an automatic thought process in the event of an emergency.


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