V-EA INTERNAL RESISTANCE
Resistances listed are “hot” values, as
opposed to cold start values. Operating
voltage drop across the V-EA and power
loss per pole can be approximated with
basic formulas:
Trip Characteristic
Rated
Current
(Amp)
B
C
D
E
G
Z
(Ohms)
(Ohms)
(Ohms)
(Ohms)
(Ohms)
(Ohms)
0.3
0.5
0.75/0.8
1.0
1.6
2.0
2.5
3.0
3.5
4.0
5.0
6.0
8.0
10
12/12.5
13
15/16
20
25
—
—
—
—
—
—
—
—
—
—
—
0.0528
—
0.0216
—
0.0113
0.0085
0.0067
0.0050
0.0032
0.0025
0.0019
0.0018
16.8620
6.8540
3.0540
1.7000
0.5870
0.4190
0.2950
0.2020
0.1390
0.1090
0.0654
0.0528
0.0278
0.0216
—
0.0084
0.0085
0.0067
0.0050
0.0032
0.0025
0.0019
0.0018
16.8620
6.0009
3.0540
1.7560
0.5870
0.4190
0.2950
0.2020
0.1390
0.1090
0.0654
0.0491
0.0240
0.0187
—
0.0085
0.0076
0.0064
0.0041
0.0027
0.0022
0.0018
0.0017
14.52000
5.92000
2.70000
1.48000
0.57400
0.40500
0.26900
0.18600
0.13900
0.10600
0.05900
0.04600
0.03040
0.02020
0.00724
0.00724
0.00731
0.00582
0.00411
0.00272
0.00212
0.00184
0.00172
16.8620
6.8540
3.0540
1.7560
0.5870
0.4190
0.2950
0.2020
0.1390
0.1090
0.0654
0.0491
0.0333
0.0211
0.0084
0.0084
0.0076
0.0064
0.0046
0.0030
0.0022
0.0019
0.00179
31.5060
10.2460
5.3920
2.6910
0.9440
0.8900
0.4290
0.3460
0.1790
0.1620
0.1050
0.0823
0.0371
0.0278
0.0151
0.0151
0.0114
0.0075
0.0050
0.0032
—
V
P
= I
= I
x R
x R
DROP
OPERATING
TABLE
TABLE
2
LOSS P/P
OPERATING
Voltage drops should be reviewed when
V-EAs with high internal resistance are
used (e.g., load voltage minimums).
Power loss should be reviewed when
V-EAs with high rated currents are used
(e.g., enclosure heating).
The listed V-EA internal resistance values
should not be used in calculations of
available short-circuit current downstream
of the V-EA. The dynamic impedance of
the V-EA under short-circuit conditions
can vary significantly from internal
resistance values in normal operation.
30/32
40
50
—
—
60/63
LINE CURRENT FREQUENCY EFFECTS ON TRIP CURVES
The thermal trip is not affected by the frequency of the line
current. The magnetic trip is within the trip zone of the
characteristic curve for frequencies from 16 2/3 to 60Hz. At
lower and higher frequencies, the magnetic trip will be delayed
longer than indicated by the characteristic curve, roughly as
follows:
Frequency Effects on Magnetic Trip Curves
Trip
Curve
Trip Zone
At
Trip Zone
At
Trip Zone
At
Trip Zone
At
Trip Zone
At
16 2/3 - 60Hz
(x RC)
100 Hz
(x RC)
200 Hz
(x RC)
400 Hz
(x RC)
DC
(x RC)
Z
B
C
G
D
E
2 - 3
3 - 5
2.2 - 3.3
3.3 - 5.5
2.4 - 3.6
3.6 - 6.0
2.8 - 4.2
4.2 - 7.0
3.0 - 4.5
4.5 - 7.5
At 100Hz: Mag. Trip Current = 1.1 x curve current
At 200Hz: Mag. Trip Current = 1.2 x curve current
At 400Hz: Mag. Trip Current = 1.4 x curve current
5 - 10
8 - 10
10 - 16
14 - 18
5.5 - 11.0
8.8 - 11.0
11.0 - 17.6
15.4 - 19.8
6.0 - 12
7.0 - 14.0
11.2 - 14.0
14.0 - 22.4
19.6 - 25.2
7.5 - 15.0
12.0 - 15.0
15.0 - 24.0
21.0 - 27.0
9.6 - 12.0
12.0 - 19.2
16.8 - 21.6
At DC:
Mag. Trip Current = 1.5 x curve current
For example, at 16 2/3 - 60 Hz the magnetic trip zone for the “G”
characteristic is 8 to 10 times the rated current of the specific
V-EA (i.e., hold for at least 100ms at 8 x RC, trip in less than
100ms at 10 x RC). With a 400Hz current, a magnetic trip at 10
x RC would be greatly delayed (thermal would likely trip first), as
the magnetic trip zone is now 11.2 to 14 x RC. If a quicker
magnetic trip is required with 400Hz, the “B” or “C” characteristic
should be considered.
MECHANICAL ENDURANCE RATINGS (ON/OFF OPERATIONS)
Application
2 x (1.15 x RC)
2 x RC
RC
No Load
Total
AC General Use
—
1000
—
6000
—
—
5000
6000
—
4000
4000
4000
4000
4000
10000
10000
10000
10000
10000
AC Motor Starting Across the Line
AC Incandescent Lamps (Tungsten)
AC Electrical Discharge Lamps (Ballast)
AC Resistance
—
—
6000
6000
—
—
Manufacturers self certification
20000 ON/OFF operations with no load
Altech Corp.® • 35 Royal Road • Flemington, NJ 08822-6000 • Phone (908)806-9400 • FAX (908)806-9490 • www.altechcorp.com
21
ALTECH [ ALTECH CORPORATION ]
