
MANUAL MOTOR STARTER GUIDE
APRIL 19
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7.6.1.5 Tap conductor protection in group installations
Please note: as of the date of this publication, the following application is not applicable in Canada under CSA C22.1
The Canadian Electrical Code (CEC), Section 28.
When manual motor starters are employed in standard group installations, their ability to protect against short- cir-
cuits is not taken into consideration. In an effort to credit these devices for protection against short- circuits, the
National Electrical Code® (NEC) allows manual motor starters marked “Suitable for Tap Conductor Protection in
Group Installations” to protect the individual group taps, instead of the upstream group BCPD. This allows the size of
the individual tap conductors to be smaller and more cost-effective than in standard group installations, as well as
the potential for larger groups and for greater disparity between individual load sizes.
When the individual load tap conductors do not exceed a distance of 3 meters (10 feet) from the BCPD before termi-
nating to a manual motor starter marked “Suitable for Tap Conductor Protection in Group Installations”, they are
allowed to be sized with and ampacity as low as 1/10 the rating of the upstream group BCPD.
The conductors between the manual motor starter and the load are sized based on the NEC rules for the load itself
and are no longer a factor of the branch circuit conductor ampacity as they are in standard group installations.
Manual motor starters marked “Suitable for Tap Conductor Protection in Group Installations” can additional be used
for the overcurrent protection of control transformers, eliminating the need for fuses or a UL 489 / CSA C22.2 No.5
circuit-breaker.
Tap conductor protection offers advantages versus conventional group installations, including:
Smaller and more cost-effective wire sizes between the BCPD and each individual load
Larger groups with greater disparity between load sizes
Protection of control transformers
Manual motor starters for tap conductor protection in group installations
Branch functional requirements
Disconnect means
Short--circuit and ground-fault protection
Tap conductor protection
Control means
Overload protection
Application information
SCCR reference for MMS: “Tap Conductor Pro-
tection”
Maximum voltage: 600
Δ
Upstream branch protection: Required
Figure 42: Manual motor starters for tap conductor protection in group installations.
Softstarter