Bayite power meter shunt wiring length

[fishboat]

When wiring up the Bayite Power Meter..




..are there any issues if the length of the wire between the negative battery pole and the shunt is 24-30 inches? I'd stay well within the 3% voltage drop guidelines...using wire two gauges larger than required. The wiring would still follow the the schematic.

[H.A.]

..are there any issues if the length of the wire between the negative battery pole and the shunt is 24-30 inches? I'd stay well within the 3% voltage drop guidelines...using wire two gauges larger than required. The wiring would still follow the the schematic.

No problem. 30 inches or 30 feet, That shunt can be anywhere on the negative side of the load.

[fishboat]

..are there any issues if the length of the wire between the negative battery pole and the shunt is 24-30 inches? I'd stay well within the 3% voltage drop guidelines...using wire two gauges larger than required. The wiring would still follow the the schematic.

No problem. 30 inches or 30 feet, That shunt can be anywhere on the negative side of the load.

Cool..thanks for responding.

[bdosborn]

No problem. 30 inches or 30 feet, That shunt can be anywhere on the negative side of the load.

Not really anywhere. The meter measures the voltage on the battery side of the shunt and uses that value to calculate power, so the results are skewed if the voltage is lower than the actual battery voltage. My Trimetric installation manual says to keep the cable as short as possible.

From the Trimetric manual:

SHUNT AND WIRING CONSIDERATIONS A shunt (a very low resistance, accurate, high power resistor) must be wired into your battery system as described in section B of these instructions. This is how current (amps) and watts are measured by this meter: The “amps” shown on the meter measures whatever current passes through this shunt—so it must be wired in series with the wire which carries the current to be measured. The shunt is almost always installed between the negative terminal of the battery and all the loads and charging sources (see Figure 1 on page 7.) It is located near the batteries, since the high current carrying wires must be kept short. The TriMetric measures the current ("amps") by measuring the very small voltage drop across this shunt. Watts measured by the meter are shown by multiplying the “volts” times the “amps”.

But, you're probably fine if you bumped the wire size up a couple of gauges. Your power results will only be off by a couple of percent, whatever percentage the voltage drop from the battery to the shunt is.

Bruce

[fishboat]

But, you're probably fine if you bumped the wire size up a couple of gauges. Your power results will only be off by a couple of percent, whatever percentage the voltage drop from the battery to the shunt is.

Bruce

Makes sense.. I've read the meter needs to be close to the shunt. Would I introduce less error if I mounted the shunt on the battery terminal and the meter 24-30 inches away? The meter wiring can be very small..(land-line telephone wire is what I was going to use), but I can easily scale that up a few gauges if needed.

[bdosborn]

The meter can go about anywhere you want, here's what Trimetric manual says about the meter wire length and size:

To install meter and shunt you will need: • One shunt (usually 500A/50mV size) •A length of cable containing 4 or 5 wires long enough to connect from battery system to meter. Or 4 or 5 individual wires may be used. (Five wires if two batteries are being measured.) The wire used for the + connection of both the main (and secondary battery if used) should have a 1A fuse at the battery end to protect the wire in case of a short. The following shows minimum size wire for distances shown: #26 gauge: 45 feet. #24 gauge: 70 feet. #22 gauge: 110 feet. #20 gauge: 180 feet. #18 gauge: 300 feet. #16 gauge: 400 feet. (These represent distances for approximately 2 ohm wire resistance.)

I put my Trimetric next to the bed so I could see it anytime I'm in the trailer.

Bruce

[fishboat]

The meter can go about anywhere you want, here's what Trimetric manual says about the meter wire length and size:

To install meter and shunt you will need: • One shunt (usually 500A/50mV size) •A length of cable containing 4 or 5 wires long enough to connect from battery system to meter. Or 4 or 5 individual wires may be used. (Five wires if two batteries are being measured.) The wire used for the + connection of both the main (and secondary battery if used) should have a 1A fuse at the battery end to protect the wire in case of a short. The following shows minimum size wire for distances shown: #26 gauge: 45 feet. #24 gauge: 70 feet. #22 gauge: 110 feet. #20 gauge: 180 feet. #18 gauge: 300 feet. #16 gauge: 400 feet. (These represent distances for approximately 2 ohm wire resistance.)

I put my Trimetric next to the bed so I could see it anytime I'm in the trailer.

Bruce

Excellent..sounds like a good plan. Thank you for your help!