Siemens I-t-e sensitrip md series Owner's manual

Bulletin SIB2.7-8

Sensitrip®

MD & ND-Frame

Information and

Instruction Guide

I-T-E®Molded Case

Circuit Breakers

I-T-E MD and ND-Frame Circuit Breakers

3-Pole, 600-1200 Amperes

Types SMD6, SND6, SHMD6, SHND6, SCMD6, SCND6

Digital Solid State Circuit Breakers

Table of Contents

Important Notices 2

General Information 3

Dimensional Reference Drawings 4

Installation Instructions 5

Operational Characteristics:

Trip Unit Adjustments 6-9

Time Current Curves 10-17

Let-Thru Curves 18

Connecting Studs 19-21

Pressure Wire Connectors 22, 23

Compression Connectors 24, 25

Handle Blocking Device 26

Handle Padlocking Device 27

Plug-In Adapters 28, 29

Mechanical Interlock 30-33

Accessories:

Shunt Trip, Undervoltage Trip,

Auxiliary Switch and Bell Alarm

Switch Installation 34, 35

Accessories (Cont’d.):

Shunt Trip and Undervoltage Trip

Mechanical and Electrical Check 36

Auxiliary Switch and Bell Alarm

Switch Mechanical and

Electrical Check 37

Rotary Handle 38, 39

Max-Flex Flange-Mount Handle Operator 40-44

TELEMAND Electric Motor Operator 45-47

Connecting Straps 48

Enclosures 49

Door Latch Mechanism 50, 51

Neutral Sensing Transformer 52,53

TS-31 Test Kit 54, 55

Ordering Information:

Circuit Breaker Catalog Numbers 56, 57

Internal Accessory Catalog Numbers 58

Additional Accessory Catalog Numbers 59

Miscellaneous:

UL Listings and File Numbers 60

Industry Specifications 60

IMPORTANT

The information contained herein is general in nature and is not intended for

specific application purposes nor is it intended as a training manual for

unqualified personnel. Refer to Note for definition of a qualified person.

It does not relieve the user of responsibility to use sound practices in

application, installation, operation and maintenance of the equipment

purchased or in personnel safety precautions. Should a conflict arise

between the general information contained in this publication and the

contentsofdrawingsorsupplementarymaterialorboth,thelattershalltake

precedence. Siemens Energy & Automation, Inc. reserves the right to make

changes in specifications shown herein or add improvements at any time

without notice or obligation.

NOTE

*Authorized and qualified personnel—

For the purpose of this manual a qualified person is one who is familiar with

the installation, construction or operation of the equipment and the hazards

involved. In addition, he has the following qualifications:

(a) is trained and authorized to de-energize, clear, ground, and tag

circuits and equipment in accordance with established safety prac-

tices.

(b) is trained in the proper care and use of protective equipment such as

rubber gloves, hard hat, safety glasses or face shields, flash clothing,

etc., in accordance with established safety practices.

SUMMARY

These instructions do not purport to cover all details or variations in

equipment, nor to provide for every possible contingency to be met in

connection with installation, operation, or maintenance. Should further

information be desired or should particular problems arise which are not

covered sufficiently for the purchaser’s purposes, the matter should be

referred to the local sales office, listed on back of this instruction guide.

The contents of this instruction manual shall not become part of or modify

any prior or existing agreement, commitment or relationship. The sales

contract contains the entire obligation of Siemens Energy & Automation,

Inc. The warranty contained in the contract between the parties is the sole

warranty of Siemens Energy & Automation, Inc. Any statements contained

herein do not create new warranties or modify the existing warranty.

Information and Instructions

General

MD and ND-Frame Solid State Sensitrip style breakers of the

Sentron family, as shown on page 5, are for use in individual

enclosures, switchboards, and power distribution panel

boards. They are available both as 80% and 100% rated

devicesand in three interruption ranges as shown in the table

below.

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Symmetrical RMS Amperes UL Interruption Ratings

Interruption

Rating Type 240V AC 480V AC 600V AC

Standard SMD6-SND6 65kA 50kA 25kA

High Rating SHMD6-SHND6 100kA 65kA 50kA

Current Limiting SCMD6-SCND6 200kA 100kA* 65kA*

*Not current limiting at 480 v AC and 600 v AC

SCMD6 and SCND6 type circuit breakers are designed to

meet the requirement of current limiting as outlined in the

National Electric Code, article 240-11 (1) and UL 489(2)

standards. SCMD6 and SCND6 type circuit breakers are

fuseless and therefore eliminate the requirement of locating

and replacing blown fuses should a high current fault occur.

The common trip feature of the circuit breaker is completely

retained so that all poles of the circuit breaker open when

caused to trip due to an overcurrent condition.

Pressure wire connectors, suitable for use with aluminum or

copper wire are available for all MD and ND-Frame circuit

breakers. Rear connection studs or plug-in connector(3)

assemblies are also available. The latter mounting arrange-

ment permits the removal of the circuit breaker from its leads

without physically coming in contact with either the line or

load terminals. UL listed special features such as a shunt trip,

auxiliary and alarm switches and undervoltage trip devices

are available for internal mounting. The installation and/or

removal of these devices is to be accomplished by qualified

personnel only. Information concerning special features can

be found on page 58.

The chart below illustrates the functions available in all

Sentron Solid State Sensitrip circuit breakers.

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Adjustments Breaker Suffix Letters

AAG ANT ANGT

Long Time Adj.

Current Setting ✓ ✓ ✓ ✓

Adj.

Long Time Delay ✓ ✓ ✓ ✓

Adj.

Instantaneous

Setting ✓ ✓ ✓ ✓

Adj.

Short Time Pick Up ✓ ✓

Adj.

Short Time Delay ✓ ✓

Adj.

Short Time I²t

Pick Up ✓ ✓

Adj.

Ground Fault

Pick Up ✓ ✓

Adj.

Ground Fault Delay ✓ ✓

General Information

Circuit Breaker Operation

With the mechanism latched and the contacts open, the

operating handle will be in the OFF position. Moving the

handletotheONpositionclosesthecontactsandestablishes

a circuit through the circuit breaker. Under overload or short

circuit conditions sufficient to trip or open the breaker auto-

matically, the operating handle moves to a position between

ON and OFF To relatch the circuit breaker after automatic

operation, move the operating handle to the extreme OFF

position. The circuit breaker is now ready for reclosing.

The overcenter toggle mechanism is trip free of the operating

handle. The circuit breaker therefore, cannot be held closed

bymeansofthehandleshouldatrippingconditionexist.After

automatic operation, the handle will assume an intermediate

position between ON and OFF, thus displaying a clear

indication of tripping.

Maintenance

Experience has shown that properly applied molded case

circuit breakers normally do not require maintenance. How-

ever, some industrial users may choose to establish an

inspection and maintenance procedure to be carried out on

a regular basis. For detailed information, consult applicable

NEMA publications or your local Siemens sales office.

(1) National Electrical Code (240-11) A current limiting overcurrent protective device, which,

when interrupting currents in its current limiting range, will reduce the current flowing in the

faulted circuit to a magnitude substantially less than that obtainable in the same circuit, if the

device were replaced with a solid conductor having comparable impedance.

(2)UnderwritersLaboratories(UL489,Par2.5)Acircuitbreakerthatdoesnotemployafusible

elementandthatwhenoperatingwithinitscurrentlimitingrange,limitsthelet-through12tto

a value less than the I2t of a 1/2 cycle wave of the symmetrical prospective current.

(3) Plug-in assembly not available for ND-Frame

I-T-E Sensitrip Digital Circuit Breaker

MD and ND-Frame Outline Drawings(1)

3-Pole

I-T-E MD and ND-Frame Installation Instructions

General

NOTE: This instruction page outlines the recommended

installation procedure.

The MD and ND Frame circuit breaker line includes types

SMD6, SHMD6, SCMD6, SND6, SHND6 and SCND6 circuit

breaker types. These devices are rated for operating volt-

ages up to 600 V AC, 50/60Hz.

Installation of Breaker

SMD and SND Circuit Breaker devices are for use in indi-

vidual enclosures, panelboards, switchboards or other ap-

proved equipment.

The installation procedure consists of inspecting, attaching

required accessories, mounting the device and connecting

and torquing the line and load wire connectors.

Mounting hardware and unmounted wire connectors (where

required) are available as separate catalog items.

A. Turn off and lock out all power before installing or

servicing.

B. Make sure that the device is suitable for the installation

by comparing nameplate ratings with system require-

ments. Inspect the device for completeness and check

for any damage before mounting.

C. Device must be in TRIPPED or OFF position prior to

mounting.

D. To mount the device perform the following steps:

1. For individual enclosures, panelboards and switch-

boards manufactured by Siemens Energy & Auto-

mation, Inc., follow the instructions provided with

this equipment.

2. For those applications where mounting is on a flat

surface of the customers equipment, drill and tap

mounting bolt holes according to the drilling plan in

Figure 1. For handle escutcheon cut out plans refer

to Figure 2.

3. If device contains internal accessories, make sure

terminalscanbeconnectedwhenthecircuitbreaker

is mounted.

4. Position device on mounting surface.

5. Installmountingscrewsand washers.Tighten hard-

ware securely.

5. After mounting the device, line and load terminals

and accessory terminals should be connected.

6. After the device is installed, check all mounting

hardware for secureness. Check wire connectors

for correct torque requirements. Torque values for

lineandloadconnectors are provided on the device

nameplate.

Figure 1

Figure 2

MD and ND-Frame Trip Adjustments

Figure 1

In= Maximum circuit breaker ampere rating.

Ir= Current Rating—a function of continuous ampere adjust-

ment setting expressed in % of In

Adjustable Long Time Delay

Seconds @ 6 x Ir

SMD/SND models with an adjustable long time delay switch

allow for selection of long time delays of fixed time intervals

at six times the continuous amps setting (1,). See Figure 1 for

the possible settings for this switch.

Ig= Ground Fault Pickup—a function of adjustment setting

expressed in % of In.

Adjustable Continuous Amps Switch

Ir= %In

All SMD-SND solid state molded case circuit breakers have

an adjustable continuous amps rating switch. Adjustments

made to this switch can change the continuous amps rating

of the breaker to 20, 30, 40, 50, 60, 70, 80 or 90% of the

maximum continuous amps rating (In) of the circuit breaker.

See Figure 1 for the possible settings for this switch.

MD and ND-Frame Trip Adjustments

Figure 1

In= Maximum circuit breaker ampere rating.

Ir= Current Rating—a function of continuous ampere adjust-

ment setting expressed in % of In

Adjustable Short Time Pickup

x Ir

SMD/SND models with an adjustable short time pickup

switch allow for selection of short time pickup in a range from

1.5 to 10 times the setting of the Adjustable Continuous

Amps Switch. The OFF position disables the function. See

Figure 1 for the possible settings for this switch.

Ig= Ground Fault Pickup—a function of adjustment setting

expressed in % of In.

Adjustable Short Time Delay

Seconds

SMD/SND models with an adjustable short time delay switch

allow for selection from two modes of short time delays. The

first range of settings enable the breaker to be set for fixed

time delays of .05, .1, .2, .3 or .5 seconds. The second range

of settings enable the breaker to be set for short time delays

basedon12tcurvesatsixtimesthecontinuousampssetting.

See Figure 1 for possible settings for this switch.

MD and ND-Frame Trip Adjustments

Figure 1

In= Maximum circuit breaker ampere rating.

Ir= Current Rating—a function of continuous ampere adjust-

ment setting expressed in % of In

Adjustable Instantaneous Trip Switch

x Ir

Instantaneous settings are multiples of the continuous cur-

rent setting.

NOTE: Maximum instantaneous trip is 10,000 Amps—with

instantaneous setting on “MAX”, time delay is eliminated.

Ig= Ground Fault Pickup—a function of adjustment setting

expressed in % of In.

Adjustable Ground Fault Pickup

Pickup Ig=%In

Delay 12t @ 51n

Ground fault protection is available for 3 phase, 3 wire and 3

phase 4 wire (neutral) electrical systems. SMD/SND models

with an adjustable ground fault delay switch allow for the

selection of ground fault pickup at 20, 25, 30, 40, 55 or 70%

of the maximum amps rating (%In), with an 12t delay of .1, .2,

or .4 sec @ .5 x InSee Figure 1 for possible settings for this

switch