Bose MR-J2S- B instruction manual Leakage current breaker Selection method

12. OPTIONS AND AUXILIARY EQUIPMENT

12.2.7 Leakage current breaker

(1)Selection method

High-frequency chopper currents controlled by pulse width modulation flow in the AC servo circuits. Leakage currents containing harmonic contents are larger than those of the motor which is run with a commercial power supply.

Select a leakage current breaker according to the following formula, and ground the servo amplifier, servo motor, etc. securely.

Make the input and output cables as short as possible, and also make the grounding cable as long as possible (about 30cm (11.8 in)) to minimize leakage currents.

Rated sensitivity current

10 {Ig1

Ign Iga K

(Ig2

Igm)} [mA] ..........(12.2)

Cable

K: Constant considering the harmonic contents

Leakage current breaker

NV

Noise

Type

Mitsubishi

K

products

filter

Cable

Servo

SM

Models provided with

amplifier

NV-SF

1

harmonic and surge

NV-CF

reduction techniques

NV-CA

Ig1 Ign

Iga

Ig2

Igm

General models

NV-CS

3

NV-SS

Ig1:

Leakage current on the electric channel from the leakage current breaker to the input terminals

of the servo amplifier (Found from Fig. 12.1.)

Ig2:

Leakage current on the electric channel from the output terminals of the servo amplifier to the

servo motor (Found from Fig. 12.1.)

Ign:

Leakage current when a filter is connected to the input side (4.4mA per one FR-BIF)

Iga:

Leakage current of the servo amplifier (Found from Table 12.6.)

Igm:

Leakage current of the servo motor (Found from Table 12.5.)

	120
current	100
	80
Leakage
	60
	40
[mA] 20
	0
		3.5	8 1422 38 80 150
	2
			5.5	30 60 100

Cable size[mm2]

Fig. 12.1 Leakage current example (Ig1, Ig2) for CV cable run in metal conduit

Table 12.5 Servo motor's

	leakage current
	example (Igm)
Servo motor		Leakage
output [kW]		current [mA]
0.05 to 0.5		0.1
0.6 to 1.0		0.1
1.2 to 2.2		0.2
3 to 3.5		0.3
5		0.5
7		0.7

Table 12.6 Servo amplifier's leakage current example (Iga)

Servo amplifier	Leakage current
capacity [kW]		[mA]
0.1 to 0.6		0.1
0.7 to 3.5		0.15
5 to 7		2
Table 12.7 Leakage circuit breaker selection example
			Rated sensitivity
Servo amplifier			current of leakage
			circuit breaker [mA]
MR-J2S-10B to MR-J2S-350B			15
MR-J2S-10B1 to MR-J2S-40B1
MR-J2S-500B			30
MR-J2S-700B			50

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