Motor Circuit Protectors

PowerPact® H- and J-frame Electronic Motor Circuit Protectors

Class 611 / Refer to Catalog 0611CT0401

PowerPact H- and J-frame electronic Motor Circuit Protectors (MCP) are magnetic-only instantaneous-trip circuit breakers. They are designed to offer short circuit protection and are National Electrical Code (NEC) compliant when installed as part of a combination controller having motor overload protection. MCP circuit breakers accept the same accessories and terminals as the equivalent thermal-magnetic circuit breakers.

Determine the hp rating from the nameplate of the motor. Select a MCP with an ampere rating recommended for the hp and voltage involved. When using the automatic settings the MCP microprocessor automatically adjusts the trip settings for both current and time to align with the start-up characteristic for the motor type, whether it is a standard or energy-efficient motor. This includes a dampening means to accommodate a transient motor in-rush current without nuisance tripping of the circuit breaker.

Table 7.60:

H- and J-frame Electronic Motor Circuit Protectors (MCP)

Frame

Current

Full Load Amperes Range

Adjustable Instantaneous Trip Range

Suffix

J Interrupting

(See SCCR Table Below)

L Interrupting

(See SCCR Table Below)

1.5–25 A

9–325 A

14–42 A

84–546 A

30–80 A

180–1040 A

58–130 A

348–1690 A

114–217 A

684–2500 A

Table 7.61:

Maximum Rating or Setting of Motor Protective Devicesa

Type of Motor

Percentage of Full-load Current

a	Based on 2005 NEC Table 430.52.

See NEC Exception No. 1 to Table 430.52. The NEC 1300% maximum setting may be inadequate for instantaneous trip circuit breakers to withstand current surges typical of the magnetization current of autotransformer type reduced voltage starters, or open transition wye-delta starters during transfer from “start” to “run,” constant hp multi-speed motors, and motors labeled “high efficiency.”

Table 7.62:

MCP Selection by HP Ratingsc of Induction-type Squirrel-Cage and Wound-rotor Motorsd

.5–5

.5–7.5

.75–15

1–20

1.5–25

M71

5–10

5–15

10–30

15–40

14–42

M72

10–25

15–30

25–60

30–75

30–80

M73

20–40

25–50

50–100

60–125

58–130

M74

40–60

50–75

100–150

125–200

114–217

M75

c	Based on 2005 NEC Table 430.250.

d	Per NEC 430.3, part-winding motors should select two circuit breakers, each at not more than one-half the allowable trip setting for the horsepower rating. The two circuit breakers should operate simultaneously as a disconnecting means per NEC 430.103.

e	Listed voltages are rated motor voltages. Corresponding system voltages are 200 Vac, 220–240 Vac, 440–480 Vac and 550–600 Vac. Select wire and circuit breakers based on horsepower rather than nameplate full-load current per NEC 430.6 (A) for general motor applications.

Short Circuit Current Rating (SCCR)

Tested to meet NEC and UL508A requirements for short circuit current ratings as part of an approved combination controller.

Table 7.63:

Short Circuit Current Ratings (SCCR)

200–240 Vac

200–240 Vac

Tesys D-line and F-line

See www.us.schneider-electric.com for specific ratings and combination ID numbers.


DE2	Discount Schedule

Related Topics: Accessories Page 7-35; Optional Lugs Page 7-38; Dimensions Page 7-54; Enclosures Page 7-55

Square D > On-line Catalog > Products > Miniature and Molded Case Circuit Breakers > Motor Circuit Protectors: PowerPact® H- and J-frame Electronic Motor Circuit Protectors	Search