Yet another solenoid bites the dust!

[John_Canfield]

Harry - we were seeing electrical bay temps at or above 120 degrees which is right at the upper operating limit for our Xantrex RS2000.

As a bonus, our positive pressure in the electrical bay should prevent water intrusion that we would see from running in wet weather.

On your 3rd Dimensions? Hmmm - there is a root cause that needs to be discovered.

[wagonmaster2]

John - If there is no "gen auto start" and never have to use the Battery Booster on the dash, would a person ever know their solenoid was kaput? And if the chassis batteries are good, can you tell if it helps to use the Battery Booster while starting the engine, or if the switch is really working? Should a person use the Battery Booster once in a while just to keep it in working order?
Thanks for helping inform a non-electrical person.
Wagonmaster2

[Harry B]

John, each failure was different.

1st unit - Fan would not run at times causing over temp.

2nd unit - Over charging during float at times.

3rd unit - No problems so far.

What I did notice looking at the Dimensions 2000 specs. is that the operating max. temperature is 104 degrees F.

This is lower than the Xantrex RS2000 (122 degrees F) and the temperatures you have measured exceeded the Dimensions 2000 104 degree F max.

I am not sure at what temperature the Dimensions 2000 would indicate an over-temp. situation. I have not seen this anymore since the 1st unit. It might be an interesting question to ask them.

[cbeierl]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by wagonmaster2:
John - If there is no "gen auto start" and never have to use the Battery Booster on the dash, would a person ever know their solenoid was kaput? And if the chassis batteries are good, can you tell if it helps to use the Battery Booster while starting the engine, or if the switch is really working? Should a person use the Battery Booster once in a while just to keep it in working order?
Thanks for helping inform a non-electrical person.
Wagonmaster2 </div></BLOCKQUOTE>

On my Vectra you can check the house battery voltage at the OnePlace panel while the engine is running--it should be at the alternator output voltage of 14+/- volts, the same as the chassis batteries. If it isn't then presumably the solenoid isn't working.

[MrTransistor]

Hi Pete,

John describes it quite well. I used 3 ea. 1 Ohm 25 Watt surface mount resistors in series for 3 Ohms. In series with the plus 12 Volt lead to the contactor. Next time I have occasion to get in there, I'll take a picture and post it.

They also make 5 and 10 Watt devices that are usually green porcelain and have leads out both ends. These may be easier to mount especially if some sort of terminal block with several screw posts is used. Use one 3 Ohm 10 Watt or two 1.5 Ohm 5 Watt or three 1 Ohm 5 Watt resistors. Remember, the resistors will get warm to hot so mount them above the contactor if possible or far below if not.

As I think back, maybe that's what I used. Seems like the dead spots in my memory are increasing!

Hi John,

Did you give up on Texas? I did a little research and came up snake eye. Looks like we're stuck with the Trombetta or $180.00 for the Blue Sea 9112. Although the Blue Sea does have certain advantages, if you already have an Eco Charge installed, it seems a rather high price to do what is already being done.

The Cole Hersee 24059BP Continuous Duty Solenoid suggested by Glenn is only rated for 85 Amps. This probably won't be enough if the boost switch is accidentally (or on purpose) activated during engine cranking.

According to Trombetta's web brochure for the ˜Bear', they haven't done anything to the coil of the 12 Volt continuous part. It's still listed as 7.7 Ohms and with 14 Volts applied that works out to 25 Watts. After several hours of driving, it's going to get pretty hot inside that contactors housing.

Hi Monte,

I may have been misleading about the coil. The coil doesn't open up but becomes hot enough to discolor or even burn the insulation around the magnet wire. Heat is an enemy of copper wire's resistance reducing the current and hence magnetism. Heat also affects the armature of the contactor increasing the magnetic reluctance and reducing the force available to pull in the contactor. Heat also speeds up the oxidation of the contacts.

My guess would be that 99% or better of all failures of this device are a result of contact oxidation and is why your procedure of toggling the contactor works. This brakes through the Copper Oxide layer.

Silver has both a lower oxidation rate and a thinner oxidation layer. Since Silver is a softer material, when the contacts close, it's very easy to break through this Silver Oxide layer. This translates to increased reliability and reduced closed contact resistance.

Hi Harry,

I replace the Dimensions inverter with a ProSine 2.0 and have now added the spare ProSine in parallel. I'm only using one unit to invert but have both units set up to charge. They can bring my 440 Amp./Hour AGM battery bank up from 50% discharge in a little over an hour. Try that with flooded batteries and they won't last long.

I knew of the heat problem soon after we got this coach so I installed a muffin fan at the foot of the bed and ducted the air into the electrical compartment with flexible dryer exhaust hose. The return is back out the top of the compartment, under the bed and out. This doesn't provide a positive pressure, a nice feature of John's setup, but does keep the compartment much cooler when needed.

For when we hit dirt roads, I installed a reversing switch on the kitchen roof fan, reversed the outside hood, and reversed the fan blades. Opening the fan door acts as an air scoop and with the fan on high and reversed, a nice high pressure is created inside the RV that can only escape through any of the cracks in the basement compartments. This keeps dust and dirt from entering any of the compartments except for the StoreMore. Of course, the windows have to be closed for this to work but it's saved us from many dusty cleanups.

wagonmaster2

Chris is correct. And if the contactor doesn't tie the batteries together after the engine starts, the house batteries are not being charged. Unless you check it occasionally, this can go on for much too long. If the inverter is left on, this can discharge the house batteries in 8 hours much lower than they should be allowed to go and will shorten their life. If you pull into a park and check the house battery voltage right after shutdown, they should read around 13.8 Volts. If you see 12.5 or less your battery tie contactor didn't work.

[PeteB]

Thanks to all for the valuable info.
When I upgraded my Inverter to the Xantrex RS3000 I moved it up from the electrical bay to under the bed. This should allow better cooling and it is easier to adapt new wiring plans. I also added some soundproofing to the area to quiet the fan noise to an acceptable level and as DW and I both like a little "white noise" when we sleep it works out very well.
Pete

[John_Canfield]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MrTransistor:
--snip--
Did you give up on Texas? I did a little research and came up snake eye. Looks like we're stuck with the Trombetta or $180.00 for the Blue Sea 9112. Although the Blue Sea does have certain advantages, if you already have an Eco Charge installed, it seems a rather high price to do what is already being done.

The Cole Hersee 24059BP Continuous Duty Solenoid suggested by Glenn is only rated for 85 Amps. This probably won't be enough if the boost switch is accidentally (or on purpose) activated during engine cranking.

According to Trombetta's web brochure for the ˜Bear', they haven't done anything to the coil of the 12 Volt continuous part. It's still listed as 7.7 Ohms and with 14 Volts applied that works out to 25 Watts. After several hours of driving, it's going to get pretty hot inside that contactors housing.--snip-- </div></BLOCKQUOTE>Mark - thanks for all the research and detailed reporting.

We are in San Diego for a wedding of Jane's girlfriend's daughter. When that is over - we are bailing. Passed a gas station here and diesel was over $5 a gallon.

There is another product called the "Battery Integrator" that I have been looking at which is a good replacement candidate.

Harry - the operating limit of 104 degrees for your Dimensions seems awfully low - if I can keep that compartment at 100 degrees, I think I'm doing a great job. Last Sunday while we were at Freightliner in Phoenix, we recorded an air temp of 104 degrees - two degrees over their operating limit

[MrTransistor]

Hi John,

Looks very interesting. The 100 Amps. continuous rating would be too low but the 200 Amp. should be sufficient for our needs. Problem is the Retail price for the BI-200 is $209.99. I got this from the New Mar sales rep. and he says they only sell through their distributors.

The only problem I can see is the Peak Maximum Current of 600 Amps. for the 200 Amp. model. This could be a problem if used for engine cranking on a low chassis battery. I'd like to see them make a 1000 Amp. model for a little less money. You could parallel two units with buss bars but then the price is doubled.

How did you find this item? I did a web search with ˜Newmar BI-200 Battery Isolator' and only got three hits, one bogus and two were the Newmar site.

Features
"¢ Enables charging of two separate banks without voltage drop, yet maintains 100%
isolation at all other times. For systems of three banks or more, an additional unit must
be installed for each additional bank
"¢ Heavy duty silver-plated contactor, continuous duty rated to 100 amps
"¢ Voltage sense circuit, epoxy encapsu- lated and heavy duty continuous rated solenoid are
all designed for use in marine environments
"¢ 12 volt model has ignition protection rating
"¢ Easy three-wire hook up for two bank systems (BATT +, BATT +, GROUND)
"¢ Terminal for optional wiring of remote light indicating when battery banks are integrated
"¢ Optional internal connection can be wired though key starter or manual over ride switch, tying
battery banks together for extra boost during engine start

Specifications
Models: BI-100; BI-200; BI-24-100
Battery Integration Connect Point: 13.2 VDC (approx.) / 26.4 VDC (approx.)
Battery Disconnect Point: 12.8 VDC (approx.) / 25.6 VDC (approx.)
Maximum Continuous Current: 100 amps (100 amp models) / 200 amps (200 amp model)
Peak Maximum Current: 400 amps (100 amp models) / 600 amps (200 amp model)
Operating Temperature: Control: -40 to +85Ëš C / Solenoid: -28 to +48Ëš C
Terminals: Battery Connections: 5/16" copper alloy stud
Dimensions: (H x W x D): 3" x 3.25" x 2.5"
Weight: 1 lb.
Approvals: CE Marked

[John_Canfield]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by MrTransistor:
--snip--
How did you find this item? I did a web search with ˜Newmar BI-200 Battery Isolator' and only got three hits, one bogus and two were the Newmar site.--snip-- </div></BLOCKQUOTE>Mark - just started Googling around and checking out marine electronics. I think Newmar's diode isolators are more popular and that's probably what returned a hit.

[SCVJeff]

Any reason to just not use diodes to get the desired drop?

[MrTransistor]

Hi Jeff,

And there is the problem, ˜drop'. In any charging system, voltage drops are not a good thing. Depending on how the system is set up, the alternator may use remote sensing to tell what the voltage is at the battery. This takes care of any drops caused by the charge current through the wiring.

But other systems don't use remote sensing and just output a voltage that should be enough to charge the battery. If a diode voltage drop is added into the circuit, then the battery receives about .8 Volts too little voltage and will be under charged.

If a ˜battery splitter' is used then both batteries will be undercharged in the second instance and in the first instance, the second battery is not sensed and may be severely undercharged.

The other consideration is current. To use diodes, they must be ratted at least for the continuous output current of the alternator. For the diesel coaches that's probably going to be 160 Amps. If the alternator has been changed out it could be a high capacity 225 Amp. unit.

[Harry B]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Any reason to just not use diodes to get the desired drop? </div></BLOCKQUOTE>
Mark,

I think what Jeff meant was to use diodes to drop the voltage to the Trombetta contactor coil.

[SCVJeff]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Harry B:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Any reason to just not use diodes to get the desired drop? </div></BLOCKQUOTE>
Mark,

I think what Jeff meant was to use diodes to drop the voltage to the Trombetta contactor coil. </div></BLOCKQUOTE>Correct.

[John_Canfield]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by SCVJeff:
Any reason to just not use diodes to get the desired drop? </div></BLOCKQUOTE>Hmmm - I don't see why not. I think the coil draws about two amps, so I'd use a diode(s) rated at about 5 amps or more. I found this link that has good prices and they look like they would be a small quantity supplier.

Recently I needed (and ordered) a bridge rectifier and the shipping was about 10 times the cost of the part. I ordered five since they were so cheap relative to shipping.

[MrTransistor]

Sorry Jeff,

A little miss-read on my part. John is correct, diodes would work well in this instance. Four five Amp. forward biased diodes in series should do the trick. That will reduce the power on the coil to below 15 Watts. There is another simple trick using diodes and a resistor, or just resistors and a capacitor to reduce the power even further. I may put some time into designing it and if I do, I'll let the community know.

[CaptBill]

I replaced my original solenoid with a Blue Seas automatic charging solenoid. It has been working flawlessly, and has the added benefit (why I installed it), to automatically charge either house or chassis bank, from what ever charging source is available; e.g. shore power, converter, generator or engine alternator.

I set mine up with a 3 position selector switch: center position-OFF (total isolation);left (momentary) position=Parallel Battery Banks (for emergency starting of engine from chassis bank or generator from engine battery); right position (latched)= Automatic.

The relay provides a voltage output for a remote LED, but I did not feel like running an additional wire to the dash, so I do not have that. The original wiring is all that is otherwise needed, with the exception of replacing the switch with the 3 position switch.

Nice to have both battery banks always charged, even in storage (when plugged in at home), without any little power cubes clipped on the battery terminals.

[John_Canfield]

Bill - that Blue Seas product looks good. I wonder what the constant current rating of it is?

[MrTransistor]

Hi All,

I just found this document from Blue Sea. Wow do they have a lot of stuff. The 7620 ACR on page 42 looks adequate for replacing the Trombetta. 300 Amp. continuous 500 Amp. intermittent and 700 Amp. cranking rating. Still, it's a bit steep a $160.00.

http://bluesea.com/files/resources/catalogs/2008.pdf

[CaptBill]

John, I believe the spec sheet that came with mine showed a constant current rating of 600 amps for 10 seconds. That could be repeated after something like a 15 sec wait. I posted some pictures of the installation and of the spec sheet here on the forum some months ago, but not sure under what topic.

[Harry B]

Does anyone know where the control logic is physically located for the Trombetta relay?

There has to be some form of control that causes the relay to engage once the alternator starts charging.