HGL Manual
4.0 Installation Guidelines
11
Since the HGL is a passive filter, it is always operating whenever the drive is operating.
Fuse Specifications
Always refer to the drawings and other information shipped with your unit. Consult applicable wiring
codes, UL and NEC, for current limiting and disconnect requirements.
SCCR Fusing Requirements
See the table below for line fusing requirements that must be supplied to comply with the
100kA SCCR.
Table 2: Customer Installed Line Fuse Requirements to comply with the 100kA SCCR
Provisional 480 V Fuse Table
The fuse tables provided below show the fuse ratings of the included branch circuit fuse internal
to the HGL unit as a fuse replacement reference.
The fuse tables also show a typical line fuse or circuit breaker current rating for overcurrent
protection, given the unit’s nameplate power rating, if necessary, based on the installation. The
line current fuses listed below are typical values given the unit power rating, not required values.
Line fusing ratings are determined by the installer, based on input conductor sizing and
protection required for downstream equipment. Any drawings or documentation included with
the unit literature kit take precedence over the fuse tables below.
Note that to achieve a 100kA SCCR, the customer provided line fuse must be installed as per
the requirements in Table 2 and sized following NEC (National Electrical Code) guidelines for
the source conductors selected by the installer. The branch fuses are required to be installed at
the shown ratings.
Warning
Only qualified electricians should carry out all electrical installation and maintenance work on the
HGL filter. Disconnect all sources of power to the drive and HGL before working on the equipment.
Do not attempt any work on a powered HGL filter.
The harmonic filter contains high voltages and capacitors. Wait at least five minutes after
disconnecting power from the filter before you attempt to service the harmonic filter. Check for
zero voltage between all terminals on the capacitors. Also, check for zero voltage between all
phases of the line side of the fuses, Fu1(a)–Fu2(a)–Fu3(a), and all input terminals L1, L2 and L3
of the line reactor (KDR). All setup, maintenance, and troubleshooting must be done by a qualified
electrician. Failure to follow standard safety procedures may result in death or serious injury.
Voltage Size
Customer Installed Line Fuse Requirements
to Comply with the 100 kA SCCR
600
≤ 40
Use appropriately rated Class J, T, or L fuse less than or equal to 60 A
600
> 40 No requirement for SCCR
480
≤
30 Use appropriately rated Class J, T, or L fuse less than or equal to 60 A
480
> 30 No requirement for SCCR
