148A from a 60A supply!!! Oh wait ...
Posted: Sat Nov 18, 2017 9:18 am
Yesterday, I replaced a -48VDC PCP charger and battery string circa 2001 with a Newmar Centurian II. I've used this product several times in the last five years. It's actually an Enatel DC plant out of New Zealand that Newmar Power rebrands in the USA. Good price, and so far a solid product.
I logged into it this morning to check the stats, and was surprised to notice the overall status screen reporting 148A from the rectifiers and to the load.
OMG!!! What did I burn down?
Oh, wait ... it's a small site that barely pulls 30A max when all stations are up. So, I put in a 50A master breaker to the load and set the rectifier to current limit at 60A. All the equipment is online. So, obviously the breaker didn't trip. It can't be exceeding 50A. When I interrogated the individual modules, their current measurements were much lower. Add them up, and move the decimal point to the right one place, and there you go - a giant number. OTOH, the event logger agrees the reported large number exceeds the alarm setpoint, and duly logs the overcurrent event once a minute.
I have a tech support question into Newmar on how to get a decimal point. Maybe it's a purchased entitlement or something.
I logged into it this morning to check the stats, and was surprised to notice the overall status screen reporting 148A from the rectifiers and to the load.
OMG!!! What did I burn down?
Oh, wait ... it's a small site that barely pulls 30A max when all stations are up. So, I put in a 50A master breaker to the load and set the rectifier to current limit at 60A. All the equipment is online. So, obviously the breaker didn't trip. It can't be exceeding 50A. When I interrogated the individual modules, their current measurements were much lower. Add them up, and move the decimal point to the right one place, and there you go - a giant number. OTOH, the event logger agrees the reported large number exceeds the alarm setpoint, and duly logs the overcurrent event once a minute.
I have a tech support question into Newmar on how to get a decimal point. Maybe it's a purchased entitlement or something.