| Author |
Message |
Wayne Buttress (Flyingb) (66.52.189.100)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 02, 2002 - 7:46 pm: | |
Happy New Year guys,
Intellitec(www.intellitec.com) makes a "Bi-Directional Isolator Relay Delay-Diesel" which will charge both batteries when either one is being charged from the alternator or another power source. This can be used with up to 200 Amp alternator. My Eagle has a 300Amp alternator, so,
to use this device, I need a isolator relay rated at 300Amps and has a minimum coil resistance of 3
ohms.
Am I barking up the wrong tree or what? Where can I get an isolator relay that would work?
Thanks again for any help. Wayne |
DrivingMissLazy (65.207.109.125)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 02, 2002 - 8:17 pm: | |
I believe all three relays in this setup would have to be 300 amps, not just the isolator relay, if you want to take full advantage of your 300 amp alternator.
Richard |
DrivingMissLazy (65.207.109.125)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 02, 2002 - 8:38 pm: | |
After reading your post a little closer, and reviewing the intellitec information, it appears that the "Bi-Directional Isolator Relay Delay-Diesel" is strictly a control device and really does not care what the amperage is. The company offers only 200 amp relays so you must find an alternate source.
You indicate the relay must have a minimum coil resistance of 3 ohms. Relays are typically rated in DC operating voltage, which would be 12 volts for your application, I believe. Was this 3 ohm resistance a specification from Intellitec? If so, then they can operate a relay that the coil is rated at a maximum of 4 amps, 12 volts. This should help you in your search for 300 amp relays.
Richard |
FAST FRED (209.26.87.49)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 03, 2002 - 5:22 am: | |
Your Smart switch could operate two 200A relays in Parallel.
But then so could any ignition switches that had an acc. terminal.
A key switch would also be easier to troubbleshoot at O' Dark 30.
FAST FRED |
Wayne Buttress (Flyingb) (66.52.189.153)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 03, 2002 - 1:02 pm: | |
Hi Guys,
AS I understand, 2-200A isolateor relays in parallel to solve the need for a 300A requirement. Is this correct?
Fred, could you go into more detail about the " ignition switch" solution.
Sorry to be so dense, but I'm trying to understand what I,m am going to do before I do it.
Richard, the 3 ohm reguirement is from Intellitec.
Wayne |
FAST FRED (209.26.87.59)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 03, 2002 - 1:26 pm: | |
In every standard old RV there is a "merge" solenoid.
When the engine is OFF,
the Start and House batt systems are seperate.
After engine start , an auto style standard key switch will allow the accesories to operate.
(They don,t operate during start for a couple of reasons,
1 accesories would drain juice needed for start ,
2 the designers knew that if the
Bendex starter did not release fast enough ,
the starter becomes an unregulated generator , and can pump 80+V thru your Blapunk !}
So the wise {and cheap RV builders} use a small line from the ACC,
circuit to have the engine alt. charge the starts , and House thru the selonoid.
A few million RV's cant be wrong ,
most RV' ers know the House set gets charged ,but few know how.
You could copy this setup , if you used a wire from the gen set to close the merge solenoid ,
as well as the usual key switch.
Its loads cheaper.
FAST FRED |
DrivingMissLazy (65.207.109.84)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 03, 2002 - 3:01 pm: | |
Yes, two 200-amp solenoids in parallel will give you a 400 amp capacity solenoid, which will actually exceed your requirements.
However, there is a down side to this. First, you will need a total of six relays, two for each leg. Second, if the solenoids have a 3 ohm coil and you parallel the coils, you will now have a 1.5 ohm coil which does not meet Intellitec specifications and may burn up the controller. The fix for that would be to add three control relays that the controller operates and the control relays would then operate the solenoids. Starts getting complex.
Fred’s idea to use the ignition switch accessory contact is good, since the accessory position is open when the ignition switch is in the start position. However, if the engine does not start and you return the switch to the run position, the batteries are connected.
I personally prefer using a low-pressure oil switch with normally open contacts and operating the solenoids thru this switch. The contacts are open until about five pounds of oil pressure is generated. That way, the contactor does not close until the engine is generating oil pressure, and if the engine quits for some reason the oil pressure goes to zero and the contactors open.
If you wire thru the accessory contacts of the ignition switch (and my bus switch does not have an accessory contact) then if the engine quits, the contactor stays closed and the battery banks stay connected. The oil pressure switch is considered a fail-safe type of control circuit.
I would suggest you contact Luke at US Coach or RONTHEBUSNUT or one of the other dealers in used equipment to try and find the appropriate contactor.
You would need only one contactor to connect the house batteries to the starting batteries. A "JUMP" switch could be used to connect the battery banks together in case the start batteries ever are down.
I would forget about the Intellitec controller and obtain a three stage voltage regulator for the bus alternator with the money you saved.
Richard |
Steven Gibbs (12.148.43.6)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 04, 2002 - 10:31 am: | |
Wayne,
I don't think you need 300 amp relays just because your alt can put out a maximum of 300 amps. If that was the case then all of your wiring between the two battery banks would have to be something like 000 or 0000 gauge cable.
The question is would the house bank ever be able to pull more that 200 amps during charging? and do you have anything on your house bank that could pull that much load? Even the inverter would not yank that much power all at once.
The main advantage to the Intellitec system is that it is really looking for a charge condition on Either bank. So your starting batteries can be charged and maintained by you house charging system (although, I have put a small disconnect swtich on the relay coil so that I can override this function).
Talk to Intellitec and see what they recommend.
Steve |
DrivingMissLazy (65.207.109.181)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 04, 2002 - 11:16 am: | |
Whether you need the full 300 amps depends on a couple of things.
I have seen installations with 6 or 8 8-D house batteries which could easily draw 300 amp charging current for a relatively short period of time. This would be in addition to the current that the starting batteries would be drawing. If driving at night, the lighting load would also be added to this.
300 amps at 12 volts is only 3600 watts. If you are wanting to run a couple of roof airs thru an inverter, you will need the full 300 amp capacity of the engine alternator.
I really think the black box is a rip off. With the addition of a good, three stage, voltage regulator for the alternator the banks can be connected together for charging, whether by the inverter or by the alternator.
Granted, a means of manually disconnecting them, with a switch, is desirable.
Richard |
Jim Lawrence (24.69.9.130)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, January 04, 2002 - 7:31 pm: | |
I use the setup that connects with ign. switch. The switch keys a continuous duty 200 amp solenoid. Unlike most setups, the 175 amp alternator first charges the house battery bank (24v), then switched to connect the starting batteries. To date I've had no trouble with setup other than a corroded batter connection. Three years has passed.
CAUTION...ensure you protect your charging system with the proper sized maxi-fuse.
When I first wired a very large solenoid into DAFfy's system, the solenoid (new) failed causing a solenoid meltdown (literally) which caused molten metal to drop onto a large battery bank which caused a very scarry fire...I was fortunate to be there to extinguish it with a fire fighting thingy.
I learned the hard way....not the smart way.
Otherwise this setup works really well. If I was to do it again, I would lean towards the oil pressure switch setup just to insert the delay od switching. |
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