Leakage Currents; To-Earth (Ground) Leakage Currents; Line Leakage Current; Harmonic Suppression Guideline In Japan - Mitsubishi Electric FR-A700 Manual

Leakage currents

Capacitances exist between the inverter I/O cables, other cables
and earth and in the motor, through which a leakage current flows.
Since its value depends on the static capacitances, carrier
frequency, etc., low acoustic noise operation at the increased
carrier frequency of the inverter will increase the leakage current.
Therefore, take the following measures. Select the earth leakage
current breaker according
independently of the carrier frequency setting.

To-earth (ground) leakage currents

Type Influence and Measures
⋅ Leakage currents may flow not only into the inverter's own line
but also into the other lines through the earth (ground) cable,
etc.These leakage currents may operate earth (ground) leakage
circuit breakers and earth leakage relays unnecessarily.
Countermeasures
⋅ If the carrier frequency setting is high, decrease the Pr.72
Influence
and PWM frequency selection setting.
measures Note that motor noise increases. Select Pr.240 Soft-PWM
operation selection to make the sound inoffensive.
⋅ By using earth leakage circuit breakers designed for
harmonic and surge suppression in the inverter's own line
and other line, operation can be performed with the carrier
frequency kept high (with low noise).
NV1
Power
supply
Leakage
Undesirable
breaker
current path
NV2
Leakage
breaker

Line leakage current

Type Influence and Measures
⋅ This leakage current flows via a static capacitance
between the inverter output cables.
⋅ The external thermal relay may be operated unnecessarily
by the harmonics of the leakage current. When the wiring
length is long (50m or more) for the 400V class small-
capacity model (7.5kW or less), the external thermal relay
is likely to operate unnecessarily because the ratio of the
leakage current to the rated motor current increases.
Influence and
Countermeasures
measures
⋅ Use Pr.9 Electronic thermal O/L relay.
⋅ If the carrier frequency setting is high, decrease the Pr.72
PWM frequency selection setting.
Note that motor noise increases. Select Pr.240 Soft-PWM
operation selection to make the sound inoffensive.
To ensure that the motor is protected against line-to-line
leakage currents, it is recommended to use a temperature
sensor to directly detect motor temperature.
MCCB MC
Power
Undesirable
supply
current path

Harmonic suppression guideline in Japan

Harmonic currents flow from the inverter to a power receiving point via a
power transformer. The harmonic suppression guideline was established
to protect other consumers from these outgoing harmonic currents.
The three-phase 200V input specifications 3.7kW or less are
previously covered by "Harmonic suppression guideline for household
appliances and general-purpose products" and other models are
covered by "Harmonic suppression guideline for consumers who
receive high voltage or special high voltage". However, the general-
purpose inverter has been excluded from the target products covered
by "Harmonic suppression guideline for household appliances and
general-purpose products" in January 2004. Later, this guideline was
repealed on September 6, 2004. All capacities of all models are now
target products of "Harmonic suppression guideline for consumers who
receive high voltage or special high voltage".
⋅
"Harmonic suppression guideline for consumers who receive high
voltage or special high voltage"
This guideline sets forth the maximum values of harmonic currents
outgoing from a high-voltage or especially high-voltage consumer who
will install, add or renew harmonic generating equipment. If any of the
maximum values is exceeded, this guideline requires that consumer to
take certain suppression measures.
Users who use models other than the target models are not covered by
the guideline.
However, we ask to connect an AC reactor or a DC reactor as before to
the users who are not covered by the guideline.
to its rated sensitivy current,
Inverter
Motor
C
C
Motor
C
Thermal relay
Motor
Inverter IM
Line-to-line static
capacitances
Line-to-line leakage currents path
For compliance to the " Harmonic suppression guideline for consumers
who receive high voltage or special high voltage
Input Power Target
Supply Capacity
Make a judgment based on "Harmonic suppression
guideline for consumers who receive high voltage
or special high voltage" issued by the Japanese
Three-phase
Ministry of Economy, Trade and Industry (formerly
200V
Ministry of International Trade and Industry) in
September 1994 and take measures if necessary.
For calculation method of power supply harmonics,
refer to materials below.
All
Reference materials
capacities
⋅
"Harmonic suppression measures of the inverter"
Jan. 2004 JEMA :Japan Electrical
Manufacturer's Association
Three-phase
⋅
"Calculation method of harmonic current of
400V
the general-purpose inverter used by specific
consumers"
JEM-TR201 (revised in Dec. 2003): Japan
Electrical Manufacturer's Association
For compliance to "Harmonic
transistorized inverter (input current of 20A or less) for consumers
other than specific consumers" published by JEMA.
Input Power Target
Supply Capacity
Connect the AC reactor or DC reactor recommended
in a catalog or an instruction manual.
Reference materials
Three-phase 3.7kW or ⋅
"Harmonic suppression guideline of the general-
200V less
purpose inverter (input current of 20A or less)"
JEM-TR226 (enacted in Dec. 2003):Japan
Electrical Manufacturer's Association
Calculation of outgoing harmonic current
Outgoing harmonic current = fundamental wave current (value converted
×
from received power voltage) operation ratio
⋅
Operation ratio:Operation ratio = actual load factor ×operation time ratio
during 30 minutes
⋅
Harmonic content: found in Table.
Table 1:Harmonic content (values of the fundamental current is 100%)
Reactor 5th 7th 11th
Not used 65 41 8.5
Used (AC side) 38 14.5 7.4
Used (DC side) 30 13 8.4
Used (AC, DC sides) 28 9.1 7.2
Table 2:Rated capacities and outgoing harmonic currents of inverter-driven motors
Rated Outgoing Harmonic Current Converted from
Appli-
Fundamental
Rated
Wave Current
Current
cable
Capacity
Converted
[A]
Motor(
from 6.6kV (kVA)
kW)
200V 400V
(mA)
0.4 1.61 0.81 49 0.57 31.85 20.09 4.165 3.773 2.107 1.519 1.274 0.882
0.75 2.74 1.37 83 0.97 53.95 34.03 7.055 6.391 3.569 2.573 2.158 1.494
1.5 5.50 2.75 167 1.95 108.6 68.47 14.20 12.86 7.181 5.177 4.342 3.006
2.2 7.93 3.96 240 2.81 156.0 98.40 20.40 18.48 10.32 7.440 6.240 4.320
3.7 13.0 6.50 394 4.61 257.1 161.5 33.49 30.34 16.94 12.21 10.24 7.092
5.5 19.1 9.55 579 6.77 376.1 237.4 49.22 44.58 24.90 17.95 15.05 10.42
7.5 25.6 12.8 776 9.07 504.4 318.2 65.96 59.75 33.37 24.06 20.18 13.97
11 36.9 18.5 1121 13.1 728.7 459.6 95.29 86.32 48.20 34.75 29.15 20.18
15 49.8 24.9 1509 17.6 980.9 618.7 128.3 116.2 64.89 46.78 39.24 27.16
18.5 61.4 30.7 1860 21.8 1209 762.6 158.1 143.2 79.98 57.66 48.36 33.48
22 73.1 36.6 2220 25.9 1443 910.2 188.7 170.9 95.46 68.82 57.72 39.96
30 98.0 49.0 2970 34.7 1931 1218 252.5 228.7 127.7 92.07 77.22 53.46
37 121 60.4 3660 42.8 2379 1501 311.1 281.8 157.4 113.5 95.16 65.88
45 147 73.5 4450 52.1 2893 1825 378.3 342.7 191.4 138.0 115.7 80.10
55 180 89.9 5450 63.7 3543 2235 463.3 419.7 234.4 169.0 141.7 98.10
75 245 123 7455 87.2 2237 969
90 293 147 8909 104 2673 1158 748
110 357 179 10848 127 3254 1410 911
132 — 216 13091 153 3927 1702 1100 655
160 — 258 15636 183 4691 2033 1313 782
220 — 355 21515 252 6455 2797 1807 1076 1011 688
250 — 403 24424 286 7327 3175 2052 1221 1148 782
280 — 450 27273 319 8182 3545 2291 1364 1282 873
315 — 506 30667 359 9200 3987 2576 1533 1441 981
355 — 571 34606 405 10382 4499 2907 1730 1627 1107 1038 761
400 — 643 38970 456 11691 5066 3274 1949 1832 1247 1169 857
450 — 723 43818 512 13146 5696 3681 2191 2060 1402 1315 964
500 — 804 48727 570 14618 6335 4093 2436 2290 1559 1462 1072
"
Measures
suppression guideline of the
Measures
×
harmonic content
13th 17th 19th 23rd 25th
7.7 4.3 3.1 2.6 1.8
3.4 3.2 1.9 1.7 1.3
5.0 4.7 3.2 3.0 2.2
4.1 3.2 2.4 1.6 1.4
6.6kV(mA)
(No reactor, 100% operation ratio)
5th 7th 11th 13th 17th 19th 23rd 25th
626 373 350 239 224 164
445 419 285 267 196
542 510 347 325 239
615 419 393 288
735 500 469 344
645 473
733 537
818 600
920 675
92