Functional Requirements For All Motor Branch Circuits - ABB MS116 Manual

7.4 Functional requirements for all motor branch circuits

The installation standards for North America require that each motor branch circuit contains electrical components
capable of meeting four functional requirements: a disconnect means, short-circuit and ground-fault protection, a
control means, and overload protection. This can be achieved of using either multiple components or a single device.
A detailed description of the functional branch requirements will be shown in the next chapter.
Functional branch
requirements
1. Disconnect
+
2. Short-circuit
and ground-
fault protec-
+
3. Control
+
4. Overload
protection
M
1a. Local dis-
connect (if
required)
The chart above shows a graphical representation of the functional requirements for all motor branch circuits. Man-
ual motor starters are capable of meeting all of the requirements listed above. However, in order for manual motor
starters to be used for short-circuit and ground-fault protection, they must be additionally certified as Type E or F
combination motor controllers.
APR I L 19
MA N UA L MOTOR START ER G UI D E
means
Fusible dis-
connect
switches
UL 98
CSA C22.2
No.4
Fuses
tion
UL 248
CSA C22.2
No.248
means
Contactors
UL 60947-4-1
CSA C22.2
No.60947-4-1
Overload
relays
UL 60947-4-1
CSA C22.2
No.60947-4-1
Non-fusible
disconnect
switches
UL 60947-4-1
CSA C22.2
No.60947-4-1
Table 25: Functional requirements for all motor branch circuits
Components
Non-fusible Inverse-time
Molded case
disconnect circuit-break-
switches ers
UL 98 UL 489
CSA C22.2 CSA C22.2 CSA C22.2
No.4 No.5
Inverse-time
circuit-break-
ers
UL 489
CSA C22.2
No.5
Variable fre- Non-fusible
Softstarters quency disconnect
drives
UL 60947-4-1 UL 508C UL 60947-4-1
CSA C22.2 CSA C22.2 CSA C22.2
No.60947-4-1 No.274 No.60947-4-1
Universal
Manual Motor
motor con-
Starters
trollers
UL 60947-4-1 UL 60947-4-1
CSA C22.2 CSA C22.2
No.60947-4-1 No.60947-4-1
...or any
shown above
next to
1. disconnect
Manual motor
means
starters
UL 60947-4-1
CSA C22.2
No.60947-4-1
Manual mo- Combination Mo-
switches tor starters
UL 489 UL 60947-4-1
CSA C22.2
No.5 No.60947-4-1
MMS only
Combination Mo-
when Type E
or F
Manual mo- Combination Mo-
tor starters
switches
UL 60947-4-1
CSA C22.2
No.60947-4-1
Combination Mo-
Combination
Motor Con-
trollers
tor Controllers
UL 60947-4-1
CSA C22.2
No.60947-4-1
tor Controllers
UL 60947-4-1
CSA C22.2
No.60947-4-1
tor Controllers
UL 60947-4-1
CSA C22.2
No.60947-4-1
tor Controllers
UL 60947-4-1
CSA C22.2
No.60947-4-1
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