Integral solid state short circuit protection does not provide branch circuit
protection. Branch circuit protection must be provided in accordance
with the Manufacturer’s instructions, National Electrical Code (NFPA70
or CSA22.1), and any additional local codes.
The minimum voltage rating for protection devices used with 240V inverters
shall be 250VAC. The minimum voltage rating for protection devices with 480V
inverters shall be 600VAC.
Fuses shall not be installed between the drive and the motor.
In PM motor applications where the drive input current can be lower than the
output current, it is allowed to use a protection device with a lower current
rating thus being able to optimize line side wiring and ancillary components.
If the controller/elevator drive is supplied through an individual isolation
transformer, the maximum fuse amperage rating shall not be greater than
125% of the secondary current rating of the transformer per NFPA70 and
CSA 22.1. This value may be signicantly lower than the values in the
following tables.
Branch circuit protection for the F5 must be provided using the fuses
listed in tables 2.2.4.1 and 2.2.4.2 below. Fast Acting class J fuses are
recommended due to size and trip speed. Note the amperage value is
the maximum value. Lower values may be used based on the relative
sizing of the motor to the inverter. If there is an isolation transformer and
a harmonic lter installed, a high speed class J fuse must be used (only
Ferraz type HSJ or Bussmann type XXXX are approved).
Table 2.2.4.1 - 230V Units
SCCR UL 248 Semiconductor
Unit Size /
Housing
[kA] rms Class J Rating [A] Fuse Number* / Rating [A]
13 / E 10 40
50 140 06 80 / 80
14 / G 10 50
50 140 06 100 / 100
15 / G, H 10, 18 70
50 140 06 80 / 80
16 / H 18 90 - -
17 / H 18 110 - -
18 / R 100 125 - -
19 / R 100 150 - -
20 / R 100 175 - -
21 / R 100 200 - -
23 / U 100 350 - -
* Semiconductor fuses are manufactured by Siba Fuse Inc. When using this type of fuse,
this is the model number of the fuse that must be used.
2.2.4 Fusing
Technical Information
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