Idea for Direct Drive unit in my Ambulance

[AshleyMckendree]

I love the Mercedes TM... it has been virtually trouble free since we built it. Not one break-down since we built it almost a year ago...

BUT floor space is at such a premium, and we have all of the parts ready to build a Direct Drive unit... My IDEA is, since the Ambulance has a 15 amp 1000watt inverter and a HUGE alternator, I could run an Electric Direct drive pump, ONE to avoid burnt belts, TWO to keep an extra 10+HP off of my DD Clutch that the pump will demand...

Three, I could put the pump anywhere I please.


P.S. this is no cheap harbor freight inverter... they run 1500 bucks.

 

[dgardner]

Ashley,

Your numbers don't add up. For 1000 W at 120 volts the current available is only 8.3 amps (A = W / V). To get 15A as your post mentions, would require an 1800W inverter.

With 8.3A available, a 1/2 horse pump will be the max you will be able to drive. This would be good for about 1.5 gpm/500 psi tops.

Assuming 90% efficiency (typical for many inverters), your 1000W inverter will draw 92 amps from the battery/alternator - 1800W will draw 167 amps, both numbers are at full load. These loads will severely shorten the life of your alternator, factor in the replacement cost. You must also consider the RPM you run the machine at - a 200A alternator needs a certain minimum RPM to achieve rated output (don't know that number off the top of my head).

Hope this helps.

PS - What pump are you using, and do you dual wand or pressure wash? My catalog shows a CAT290, for instance, uses barely over 2HP at 3 gpm and 1000 psi.

 

[AshleyMckendree]

Thanks for the input... the 15amp rating is for the built in battery charger, I misread it.

Im running a T Series General Pump... looked it up and it only demands a little under 5hp.

 

[Art Kelley]

I love the Mercedes TM... I could run an Electric Direct drive pump, ONE to avoid burnt belts, TWO to keep an extra 10+HP off of my DD Clutch that the pump will demand...

Three, I could put the pump anywhere I please.


P.S. this is no cheap harbor freight inverter... they run 1500 bucks.

If you have a Ford or GM, White Magic makes a front end kit for DD that's really reliable. My belts for the pump and vac are still good after 6000 hrs, I've replace the engine serpintine belt once but didn't need to. The electric clutch is heavy duty.

 

[Supersucker]

Ashley is that a Ford Diesel, with twin alternators? If so you may be able to produce the juice but do make sure you have a big inverter so that it will last.

Dose an ambulance spec van not have a trans PTO?

On the other hand, since we all know how handy you are, why not mount the pump on the motor with its own clutch?

 

[AshleyMckendree]

What does this "Kit" consist of?

It is a Ford 7.3 Diesel. Just one BIG alternator.

The shaft I have is a white magic shaft.


I do not believe it has a trans PTO.

 

[Art Kelley]

What does this "Kit" consist of?

It is a Ford 7.3 Diesel. Just one BIG alternator.

The shaft I have is a white magic shaft.


I do not believe it has a trans PTO.

I don't know what's in a kit, but it sounds cool. Costs about $3500, turns a van into a PTO. Call a WM distributor and see if it will work for you. There'd be no monkeying around with an electric supply for the pump. Use a Cat Pump that will last 20000 hours.