Figure 6.2 typical emergency stop circuit – Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set User Manual

Page 339

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Section 6

Emergency STOP Design

6-3

Figure 6.2

Typical Emergency Stop Circuit

MTB PANEL

Motherboard/Processor Board

MACHINE

DRIVES ENCLOSURE

SYSTEM INSTALLER OPTIONS

Motor thermal switches

may be connected

directly

Extreme overtravel

switches

Reset

button

E-Stop

button

Contactors for E-Stop status controlled

devices (servo amp contactor, indicators,

brakes, coolant pumps, etc.)

Drive System Ready

Remote

E-Stop

button

15 V dc

from main

power supply

Reduced

to 12 V dc

filter

250mA

E-Stop relay K

1

12 V dc coil

Contact ratings:

30 V dc

1.4 A

Software

controlled

E-Stop

circuit

K

1B

K

1A

1

2

3

4

5

6

7

common

Customer-supplied

dc power

CR

CR

+

--

customer supplied

fuse (size to protect K1b

contact and your E-Stop

status relay)

E-Stop status

relay

8

If your control has terminal 8, connect it

to chassis ground. If terminal 8 is not

present on your control, then this type of

grounding is not necessary.

Important:

Connections to all pins on the 9/Series E--Stop

terminal are DC only. AC connection to any of these
terminals can cause damage to your 9/Series CNC.

Important: We recommend that all contactors used on the 12V E-Stop

string are rated for use at low level operation (dry circuit contactors). This

may increase initial expense of the circuit but will provide more reliable

E-Stop string operation over time. Use of non-dry E-Stop devices may

result in nuisance E-Stop faults or failure to establish a closed circuit when

the E-Stop reset push button is closed. Corrosion build-up on non-dry

contactors are not cleaned by the control’s operation. Dry contactors are

more immune to corrosive effects.

If non-dry contactor devices are used as elements of the E-Stop string, we

recommend the use of a pilot relay in conjunction with a

customer-supplied power supply operating independent of the control’s 12

Vdc string. Select a pilot relay with a dry contact rated for use in the

E-Stop string.

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