Mitsubishi FR - S500 Type SP, CF, SF, CP, Rated sensitivity current, ∆ n ≥ 10 ⋅ lg1+Ign+lg2+lgm

(3) Selecting the rated sensitivity current for the earth leakage circuit breaker

When using the earth leakage circuit breaker with the inverter circuit, select its rated sensitivity current as follows, independently of the PWM carrier frequency:

Progressive Super Series	Example of leakage	Leakage current
(Type SP, CF, SF, CP)	current per 1km in cable	example of 3-phase
Rated sensitivity current:	path during commercial	induction motor
I∆ n ≥ 10 ⋅ (lg1+Ign+lg2+lgm)	power supply operation	during commercial
Conventional NV series (Type CA,	when the CV cable is	power supply
CS, SS produced prior to '91)	routed in metal conduit	operation
Rated sensitivity current:	(200V 60Hz)	(200V 60Hz)

I∆ n ≥

10 ⋅ {lg1+lgn+3 ⋅ (lg2+lgm)}

(mA)

120

(mA)

2.0

lg1, lg2 : Leakage currents of cable

100

1.0

path during commercial

80

0.7

current

current

power supply operation

60

0.5

0.3

lgn*

: Leakage current of noise

40

0.2

filter on inverter input side

Leakage

20

Leakage

0.1

lgm

: Leakage current of motor

0

2 3.5

8 142238 80150

1.5 3.7 7.5 15223755

during commercial power

5.5

30 60100

2.2 5.5 1118.53045

supply operation

2

Cable size (mm )

Motor capacity (kW)

<Example>

2mm2 ×5m 2mm2 ×70m

(16.40feet)

(229.66feet)

NV

Noise

filter

3

Inver-

IM 200V

ter

1.5kW

(2HP)

Ig1

Ign

Ig2

Igm

CAUTION

•The earth leakage circuit breaker should be installed to the primary (power

supply) side of the inverter.

• In the connection neutral point grounded system, the sensitivity current becomes worse for ground faults in the inverter secondary side. Hence, the protective grounding of the load equipment should be 10Ω or less.

•When the breaker is installed in the secondary side of the inverter, it may be unnecessarily operated by harmonics if the effective value is less than the rating. In this case, do not install the breaker since the eddy current and hysteresis loss increase and the temperature rises.

*Note the leakage current value of the noise filter installed on the inverter input side.

	Progressive Super Series		Conventional NV
	(Type SP, CF, SF,CP)		(Type CA, CS, SS)
Leakage current (Ig1) (mA)	20 ⋅	5m (16.40feet)		= 0.10
		1000m (3280.80feet)
Leakage current (Ign) (mA)		0 (without noise filter)
Leakage current (Ig2) (mA)	20 ⋅	70m (229.66feet)		= 1.40
		1000m (3280.80feet)
Motor leakage		0.14
current (Igm) (mA)
Total leakage current (mA)	1.66			4.78
Rated sensitivity current	30			100
(mA) ( ≥ Ig ⋅ 10)

16