i don't really think it is going to make a bit of difference if it is hi or low side on the shunt,, current is theoretically equal throughout the circuit?
as for a lightening strike, i have no idea how you design around that concern,, if the lighteing gets downline past the arresters you are screwed where ever you put the shunt, or at least that is how it would appear to me.
knowing my luck after a lighting strike if i were able to save the case/chassis i would be thrilled!
bob g
The exposure to high voltage from a lightning strike can mean some very high amps through the shunt. Burning out the data logger is not the concern in this situation. A momentary 2000 Amp current from the generator to ground will cause a 200 volt potential across the shunt! That 200 Volt potential on the ground side could bias the battery backwards by 187 Volts. Boom.
The generator's negative would have to be at earth ground, and the battery's negative terminal will be "above" that ground level, in order to keep the current to ground from going through the shunt (maybe). Steven Fahey[ Parent ]
FWIW, it is more or less standard to have the shunt in the negative side in the battery monitoring systems that are installed in boats. (The Xantrex link series etc.)
This makes things a lot easier when there is more than one battery bank (engine cranking battery, generator cranking battery, house battery, electronics battery), particularly if the monitor is being retrofitted to an existing system which is often the case. There normally is (or should be) a common ground point for all the batteries and consumers and this is an easy place to install the needed shunts. Installations vary. Some monitor all batteries, others only monitor the house battery.
OwenIf you're not living on the edge, you're taking up too much space.[ Parent ]
