Quote:
Originally Posted by YC1
Paul, I am a bit curious about your comment about holding the Aux start button down for a long time.
Since these things are snow flakes I can tell you that many of the "Big Boy" solenoids are continuous duty and even thought they get really hot to the touch, heck you can't even touch mine when it is running for days.
In some cases when alternators fail it is common to prop the Aux start button to keep things running.
The BIRD information is very complex and there are dozens of variations.
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I answered this earlier today but see the posting didn't take.
Yes, many different systems and configurations, but the basics of a BIRD and BigBoy are the consistent. The BigBoy comes in several forms - lets start with latching and non-latching. The ones in our coaches are NON-latching. A latching relay gets a voltage to tell it to close and it closes, but doesn't require voltage to stay closed. It then requires a voltage on a different terminal to release, and when it sees it, it pops open. Both voltages are pulses.
Our coaches have non-latching, which require a continuous voltage on a terminal to close and STAY closed. The tricky bit, which is NOT in the documentation - is that the BOOST switch sends a 12V (or whatever is available so long as it is above 9V) to the activation terminal on the BigBoy. This voltage activates a solenoid that closes and keeps the relay closed.
The BigBoy gets hot because it can transmit up to 200 amps in charging mode. In boost applications for shorter periods it is rated for up to 1,200 amps (for 30 seconds). 1,200 amps will get it VERY warm, but that is not the issue. The problem is the small solenoid that keeps it closed.
Here is the secret I learned from Intellitec support - the BIRD unit only sends 12V for a few seconds, then it starts modulating the signal. I found this out because when I checked all my voltages I found that on initial triggering the BIRD sent 12v, but if I checked later to see if it was getting a signal, I was only getting about 1.5V. I assumed I had a bad BIRD unit. Not so, this is how it keeps from burning out the solenoid - it only needs 12V (or really 9V) for fractions of a second at a time, and to a multimeter it looks like 1.5V.
If I hadn't called Intellitec support, and been sent to some guys in Ohio who do their RV support, I'd never have known this, but it will cause the solenoid inside the BigBoy to fail.
The BigBoy also comes in 100 and 200 amp versions, but I don't think that is relevant.
There you go.
Linear Mode
