Kollmorgen MMC Smart Drive Series, Hardware Manual

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46 Kollmorgen - June 2014
MMC Smart Drive Hardware Manual
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SYSTEM POWER DEVICES
provided in accordance with the National Electrical Code and any additional local
codes, as described in this section.
Two types of Protection must be provided in case the Smart Drive malfunctions:
• Short Circuit Protection - this protection helps minimize damage to the Smart
Drive in the case of a Short Circuit condition. Short Circuit Protection is required to
meet UL508C requirements.
• Branch Circuit Over Current Protection - this protection helps minimize damage to
the Smart Drive and helps protect the wiring between the Smart Drive and the
Over Current Protection Device in the case of a sustained Over Current condition.
Over Current Protection must be provided in accordance with NFPA 79 7.2.3 and
7.2.10. Supplemental UL1007 protectors
shall not be used to provide Branch Cir-
cuit Protection.
Two types of fuses are defined for use with the 460V Smart Drive:
Non-restricted - If the Branch Circuit supplying power to the drive is capable of
delivering no more then 18,000 RMS symetrical short circuit amperes (480V
maximum), the fuse type provided for Protection has no “Clearing I
2
t” restrictions, and
must meet the following requirements:
•
have a current rating no greater than the “Maximum Fuse Size” in Table 4-5
•
have an interrupt capability no less than the short circuit rating (Prospective Short-
circuit Symetrical Amperes) of the Branch Circuit supplying the drive.
Restricted - If the Branch Circuit supplying power to the drive is capable of delivering
between 18,000 and 100,000 RMS symetrical short circuit amperes (480V maximum),
the fuse type provided for Protection has “Clearing I
2
t” restrictions, and must meet the
following requirements:
•
meet both of the requirements for a non-restricted fuse (above)
• have a “Clearing I
2
t” rating no greater than the “”Clearing I
2
t” rating in Table 4-5
The requirements for both restricted and non restricted fuses may be meet by using
one of two methods:
•
Use a single fuse that meets all requirements. The easiest way to accomplish this
is to use a “Combination Fuse” from
Table 4-5 . These fuses meet all of the
requirements for both Short Circuit Protection and Over Current Protection, and
may be used on Branch Circuits that supply up to 100,000 RMS symetrical short
circuit amperes (480V maximum).
•
Use two fuses connected in series, that, in combination, meet all of the require-
ments:
NOTE
• The 460V Smart Drive (SD) is suitable for use on a circuit capable of delivering
not more than 18,000 RMS symmetrical Amperes, 480 Volts maximum.
• The 460V Smart Drive NextGen (SDN) is suitable for use on a circuit capable of
delivering not more than 100,000 RMS symmetrical Amperes, 480 Volts
maximum, when protected by fuses, as described in this section.