voltage drop across my old circuit breaker

simonfraser said:
measures 0.2 ohm with no current being drawn across.

so if i pull 6A through that at 13V, i lose 1.2 V ?!

you're bound to correct me ....

a new breaker would not have this resistance ?
or are new spade fuses better still as far as voltage drops are concerned ?
Click to expand...

In theory but why not measure the volts across it when you have some load on.
 
simonfraser said:
measures 0.2 ohm with no current being drawn across.

so if i pull 6A through that at 13V, i lose 1.2 V ?!

you're bound to correct me ....

a new breaker would not have this resistance ?
or are new spade fuses better still as far as voltage drops are concerned ?
Click to expand...

Only if it's ohmic and you've got a meter that can really measure 0.2ohm. Even 'good' multimeters are not much use for anything below an ohm.
 
Low ohms measurement is a specialised activity which usually involves the Kelvin 4 lead method. It's easier to put a known current through and measure the drop.
 
tnx.

all resulted from the diesel hotplate not having sufficient power to switch on with 12.5V at the battery whilst starting the hob, 6A current draw according the the manual.
read 11.2V at the hob whilst trying to start. (engine on or solar on no problem)
long old run with an old circuit breaker, which i have just replaced with a new much shorter run with a blade fuse.
new cable 3m long, replaced both neutral and live, 6mm 53A size.

will check the voltage drop at the hob when starting tomorrow, was getting too dark last night to do this safely.
 
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