Originally Posted by ManWonder
I got a Blue Sea 7610 ACR to replace the failed isolator in my 2004 Roadtrek 190 Popular. It says on the packaging "120A Alternator" but the small print says it will handle up to 210 amps for 5 minutes. The alternator in the Chevy 6.0l V8 engine puts out 145 amps. So does anyone know if I need to return the 7610 and order the next one up (7620 rated for 500 amps)? The price is double so I want to make sure. TIA
A 2004 Roadtrek 190 would have an isolator so also should have only 6ga wiring to the coach and 50 amp breakers (assuming they are still working), so the 7610 should be OK. It will depend on how many, what type and brand, and condition, batteries you have when it comes to what the maximum current will try to be. Even one AGM at 20% SOC would likely try to pull a little over 50 amps when first taking charge. If the breakers are tripping, you should be able to hear the clicking of them when they trip and when they reset.
The 145 amp alternator also has to run the van electronics and engine, so it would be unlikely for it to even get to 120 amps to the coach even if the wiring and breakers allowed it.
As always, it is good to have a battery monitor so you can see just how many amps are going to the batteries.