Anyone else use an inverter in similar way?

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11-14-2005, 08:32 PM
confire

Anyone else use an inverter in similar way?

Anyone else use an inverter in similar way?

Our rescue is at the present time under construction and is is spec’ed with a 3000 watt inverter. The purpose is to power a small 110v refrigerator and a 6 bank 110v radio charger.
We want to keep bottled water in the refrigerator and think the inverter should keep it with un-interrupted power.
The inverter will get its power from the battery. In station the Kussmaul battery conditioner should keep the battery up.
We currently have the same set up on one of our engines for 8 bank radio charger and it works fine. We’ve tried two brands of 12v chargers only to have problems with them.

Anyone see why this will not work?
11-14-2005, 10:50 PM
Fyrechicken

I'd go with hooking the 120VAC powered equipment right to the shoreline, one less place of electrical equipment to fail in the rig (battery charger fails and the inverter drains your battery) or (inverter fails and your portable batteries are dead and your water is warm) plus if you go with a pto gen set on the new truck you can have that power up your 120VAC equipment as soon as you start the engine (shoreline powered in-station/pto gen set powered while on the road). Your going to find that the battery chargers are not going to have enough output to keep up with the demand of the inverter.
11-14-2005, 11:40 PM
arhaney

Our rescue used to be an ambulance, it's set up with a shore line connector. When you are plugged up on the shore line, all the plugs in the box run off of the shore line. When you start the truck and unplug it, a relay takes the power from a large inverter and powers all of the plugs in the box. (I'll check the wattage rating) We have 3 flashlight charging, a fridge, :D :D ,and a dual battery sawzall battery charger. As an extra bonus on this unit, the block heater was wired in for continuous operation while plugged into the shore line, but not when it's unplugged. Since our truck is always in a heated building, I removed the block heater plug and wired in a Kussmaul Auto Charge 12. Never a dead battery again! And only one shore line plug, not two!

Like NJTF1Bowman, I don't think your setup as listed will work........
11-14-2005, 11:49 PM
arhaney

Also, you may want to look at a Kussmaul charger that charges the battery while supplying a seperate circuit for accessories. From Kussmaul:

Quote:

The Auto Charge 20/20 is a fully automatic battery charger with a very high output for vehicles with a single battery system. Remote voltage sensing is provided to compensate the charger output for the voltage drop in the charging wires. It is ruggedly constructed for mounting in the vehicle. May be used for positive and negative ground systems.

Quote:

A 20 ampere Battery Saver is provided to power rechargeable hand lights or other accessories. The Battery Saver automatically disconnects these accessory loads from the battery and powers them from an internal power supply. This removes the accessory loads from the battery during charging.

Web Site for 20 amp charger:

http://www.kussmaul.com/091-2020.html

PLease note that this may not be enough to keep up with your inverter!
11-14-2005, 11:59 PM
arhaney

Quote:

Originally Posted by confire

Anyone else use an inverter in similar way?

We currently have the same set up on one of our engines for 8 bank radio charger and it works fine. We’ve tried two brands of 12v chargers only to have problems with them.

Anyone see why this will not work?

Missed this bit of info the first time. Sounds like your failed chargers kicked the bucket because your amperage being used is more than the charger can supply, causing it to run at full power at all times! :eek:
11-15-2005, 08:18 PM
confire

Quote:

Originally Posted by NJTF1Bowman

I'd go with hooking the 120VAC powered equipment right to the shoreline, one less place of electrical equipment to fail in the rig (battery charger fails and the inverter drains your battery) or (inverter fails and your portable batteries are dead and your water is warm) plus if you go with a pto gen set on the new truck you can have that power up your 120VAC equipment as soon as you start the engine (shoreline powered in-station/pto gen set powered while on the road). Your going to find that the battery chargers are not going to have enough output to keep up with the demand of the inverter.

You may be on right on something failing and draining the batteries. I guess time will tell on that.
The downside I see in using the shoreline, then the generator is that the starting and stopping is going to be hard on the refrigerator’s motor and condenser.

As far the amp draw, someone smarter then me says that should not be a problem do the size of the inverter.

I will do a little research on the Kussmaul battery saver.
11-16-2005, 07:00 AM
dmleblanc

Our new rescue has an Auragen 8.5KW belt driven generator. The refrigerator operates off the 110V shore line when parked in the station and plugged in. It runs off the Auragen generator when it's running. For short runs (say, a medical call where we're only going to be out for 30 minutes or so) we generally don't start the generator. Longer scenes (MVA's and structure fires) we'll start the generator and that runs the fridge.
11-20-2005, 09:21 AM
chiefeng7

Quote:

Originally Posted by confire

Anyone else use an inverter in similar way?

Our rescue is at the present time under construction and is is spec’ed with a 3000 watt inverter. The purpose is to power a small 110v refrigerator and a 6 bank 110v radio charger.
We want to keep bottled water in the refrigerator and think the inverter should keep it with un-interrupted power.
The inverter will get its power from the battery. In station the Kussmaul battery conditioner should keep the battery up.
We currently have the same set up on one of our engines for 8 bank radio charger and it works fine. We’ve tried two brands of 12v chargers only to have problems with them.

Anyone see why this will not work?

I know of at least a few problems.

First off. Lets assume that inverter does draw 3000 watts. At 12 volts, thats 250 amps. Don't believe me? Look at the HUGE wiring it needs to work. There is not a Kussmaul charger in the world that will keep up with that. You will have a battery charger running hard all the time and eventually dead batteries and a battery charger on fire. Assuming I'm wrong (and I'm not - I do this for a living), when the power goes out in your station it will be 6 minutes before the truck will be too dead to start, assuming you have 6 batteries.

You may be wondering why this works fine for a radio charger in another truck... The radio charger in another truck draws MAYBE a half of an amp at 120V, which is 5 amps from the 12V batteries. The battery charger can EASILY keep up with that. In fact, you could probably draw twice that without a problem.

Two way radio manufacturers have NOT properly addressed the need to bank charge radios in fire apparatus. Since they haven't, this is how you run the number of things you want to run:

When the truck is plugged in at the station, the shore line will directly supply your refrigerator as well as battery charger. While en route to the incident, NOTHING supplies them. Once you get there, have it in your SOGs to have the generator running. This will pick up where your shore line left off. There is no reason for this not to work, simply because refrigerators are well insulated. This also provides adequate time for the refrigerant compressor to equalize and be prepared to start up again. This transfer in power to your generator is accomplished with a simple transfer switch installed in the circuit breaker box. Your radios will not lose any significant amount of charge while en route to a call, and in fact they may benefit from the re-cycling of the charger.

Jon

Edited to add: The Kussmaul Battery Saver is NOT designed for this application. Not at ALL. This is an UNFILTERED, UNREGULATED, RIPPLE-DRENCHED supply of "DC" power that almost resembles AC power. DO NOT EVER connect anything to these devices that you value at all other than perhaps a flashlight charger. NEVER EVER EVER connect TICs, Portable Radio Chargers, Inverters, etc. to this as they are designed for clean, regulated DC power which is NOT found in the Kussmaul Battery Saver.
11-21-2005, 10:06 AM
Rescue101

Like C7 says,check the input requirements of your inverter.Most are pretty power hungry.I am NOT a fan of inverters.We have two rigs with them and both need to be run on fast idle if you're running any load on the inverter.The higher the inverter load the higher the battery draw.Particularly if you're starting loads like refrigeration,saws,etc. Kussmaul units should be regarded as "trickle"chargers because that is what they are(although a sophisticated high grade version thereof). T.C.
11-22-2005, 08:33 PM
mustang183

Vanner makes a really nice inverter with a built in charger and automatic transfer switch. Check it out here: http://www.vanner.com/htm/pro_01.htm...38312&a=a&pt=3

I've installed several of these with no problems.
11-22-2005, 09:12 PM
arhaney

Quote:

Originally Posted by mustang183

Vanner makes a really nice inverter with a built in charger and automatic transfer switch. Check it out here: http://www.vanner.com/htm/pro_01.htm...38312&a=a&pt=3

I've installed several of these with no problems.

Now that's a nice unit! Looks like the way to go. I like the built in transfer switch, less "stuff" to deal with.
11-23-2005, 12:16 AM
LeuitEFDems

Quote:

Originally Posted by mustang183

Vanner makes a really nice inverter with a built in charger and automatic transfer switch. Check it out here: http://www.vanner.com/htm/pro_01.htm...38312&a=a&pt=3

I've installed several of these with no problems.

We have these units on both of our ambulances (Brauns), very nice units. We are having an issue with our older one, people forget to turn off the flourecent lights (they work off of the shore line/Vanner) and it seems that the charger puts too much power to the lights instead of charging the batteries. We recently had to replace the 2 batteries. This won't be an issue too much longer though, our new rig is in the specing phase, and it will have time outs on the shoreline lights.
11-23-2005, 07:47 AM
chiefeng7

You notice the people that are using these units successfully are using lights. These are LOW CURRENT DRAW devices. If you have a rescue drawing 250A off the DC side en route to a call, you will be in trouble - especially if you have a Q2B on that truck. I strongly reccomend you just leave the 'fridge hanging with no power until you get to the scene. It may not be a bad idea to use one of these devices to power the portable radios though.

If you don't listen to the advice you receive on here and you do go and have the refrigerator on all the time, PLEASE make sure the manufacturer of your truck will correct it later when it doesn't work, free of charge.

Jon
11-23-2005, 08:55 AM
captain7

We have a similar setup without the inverter

Our new pumper/rescue has all the radio chargers hooked to the trucks 12v system. Our refrigerator is a dual 120v/12v which auto switches from shore power to the truck's 12v system when we are on a call. We spec'd the largest dual alternators from detroit we could get. The leece niville, I think they are 270 amp each. With the load sheading, which seems to never come on, even with the ac on, we don't have truck power problems anymore. Unlike our old macks with a single 220 amp alt. We had inverters on those trucks which kept blowing diode packs. The newer inverters are probably better than what we had.
11-23-2005, 09:29 PM
confire

Thanks for all the good input guys.

Jon, you brought up some very good points that started me making some inquires. First we checked our specs and found that we do have an automatic transfer switch. The 110v power is supplied off the shoreline in station. After the shoreline is disconnected the inverter takes over. The sales rep. is checking with the builder to confirm this.
Second, we took a looked at the draw on the fridge (it’s not really a refrigerator but a 32 bottle wine cooler with no freezer. It holds more bottles of water then a fridge of the same size). The power draw is 140 watts, 1.45 amps at 120 volts. I was unable find the draw on the bank charger or hand lights but can’t believe it could be very much.

As for the alternator, even though everything from running, brake and turn lights to all emergency lighting are LED's we still went with a 320 amp. Alt.

We like the idea of being able keep radio batteries charged up at long scenes and have not experienced and problems in the past 5 years with that.

In your opinion, with the low power usage do you think we will experience any of the problems you mention?

I’m only one voice in a four man committee :)

Side note: Now this may or may not be a good idea (time will tell) we have a 3000 watt inverter on a tanker that rums three 750 W lights. The tanker is three years old and the lights have proven to be a great asset; we only use two lights at time.
11-24-2005, 01:50 PM
chiefeng7

What you have sounds more like a thermocouple based cooler than a refrigerator. Regardless, that will work without a problem. Of your 320 amp alternator, assume 80 for a Q2B (you may not have one but whos to say it won't get added), that leaves you with 240 amps. 80 would cover the chassis, leaving you with 160 amps. If you can't power a bunch of LEDs and 15 amps to a fridge, you have bigger problems :-).

Strongly consider a transfer switch to transfer these loads to the generator once it is turned on. They're inexpensive (you have one already), and will save your DC electrical system. Even if you don't do that - looks to me like you'll be okay.

Jon
11-27-2005, 06:58 PM
Fire304

Quote:

Originally Posted by confire

we have a 3000 watt inverter on a tanker that rums three 750 W lights.

We've got a couple of older trucks with a simular set up and have constant problems of killing the batteries on scene. Problem is that the inverter plus all the emergency lighting puts out more than the alternator can produce at idle, so if you're curculating water or just at idle you turn around and the head lights are more dim orange than white. Several time's I've found inexperienced operators had let the system get so low that we had to shut down all the electrical loads and let the truck fast idle for an hour to get enough back into the batteries to turn the head lights on to drive home. Once it got so far down the alternator needed to be re-excited before it began charging again. These trucks are old enough that they don't have load shedders, which might eliminate the problem.
02-08-2006, 10:47 AM
herbroberson

A little late...

I know this is an old thread, but what do you expect out of an old guy :D .
Just my $.02 worth here, but I have never had a good experience (in 27 years now) with ANY inverter used in an emergency vehicle. They are the number one killer of batteries and alternators! If at all possible use a shoreline with an onboard generator of some kind...the hydraulic powered pto driven ones are GREAT! ;)