rectifier and bond reading tim jenkins. basic electric - shunts

Rectifier and Bond Reading

Tim Jenkins

Basic Electric - Shunts

Basic Electric - Shunt Formulas

• Calculate Current– Given - Shunt ( .01 ohms & voltage across the shunt = 50 Mv)

– Convert units of voltage, 50mv = .05v

– Calculate current using Ohm’s law• I = .05 v/.01 ohms = 5 amps

– Given - Shunt ( 15 amps, 50mV)• Measured voltage drop = 28mV

– Determine shunt rating• Rating = 15 amps/50mV = .3 amps / mV

– Calculate current• Current = .3 amps / mV x 28 mV = 8.4 amps

Slide Resister Application

Resister Wire Application

The amount of Resistance is made by the Length of the Wire.

Disconnect Bond Wire for Amp Drain Reading

Amp Drain Reading

Make Connection in series with the Circuit

1.36 Amp Current Drain

Slide Resister

Lighting Arrestor

Connection Made on Resister from Foreign Structure and Columbia.

Disconnection to get Amp Drain must be made in series with the circuit.

Direct Bond Connection, No Resistance

Shunt Resister

Measuring Amp Drain by Measuring Voltage Drop Across the Shunt. Ratio is normally found on Shunt. .001V = 1A

7 milivolts = 7 Amps

Polarity does not matter.

Make connection across Shunt.

Ratio for Shunt

Shunts do not have to be disconnected in BI-monthly and Annual inspection.

Connect meter in serious for amp reading

on the structure or anode wire.

Alternative method – use shunt for amp readings.

Take mili-volt reading across shunt then use ratio to figure total amps.