E stop vs Spring return to center

[W@ttson]

Hello,

I have a converyor belt. I have a spring return to center switch. To the left the conveyor belt goes one way, to the right it goes the other way. If I let go the conveyor belt stops because the switch springs back to the center off position.

This is on a control panel which control a bunch of different conveyors. Each conveyor has its own switch.

The control panel does not have an E stop.

I am thinking that the spring return to center is not enough to be compliant with NFPA 79 requirements.

Thoughts?

 

[ptonsparky]

Hello,

I have a converyor belt. I have a spring return to center switch. To the left the conveyor belt goes one way, to the right it goes the other way. If I let go the conveyor belt stops because the switch springs back to the center off position.

This is on a control panel which control a bunch of different conveyors. Each conveyor has its own switch.

The control panel does not have an E stop.

I am thinking that the spring return to center is not enough to be compliant with NFPA 79 requirements.

Thoughts?

I don't know about NFPA 79, but anything I did with multiple motors in a process had an Estop. Everything stopped. Nothing I worked on would have created a bigger problem when they did stop.

Spring returns don't always return.

 

[drktmplr12]

Viewing NFPA 79 is free online if you make an NFPA account.

NFPA 79: Electrical Standard for Industrial Machinery

<p>1.1* Scope. A.1.1 In this standard, the term electrical includes both electrical and electronic equipment. Requirements that apply only to electronic equipment are so identified. The general terms machine and machinery as used throughout this standard mean industrial machinery. See Annex C...

www.nfpa.org

is specifies what type of switches e-stops can be.

spring return switches do not qualify as an "e-stop"

 

[W@ttson]

Thanks for the input

 

[petersonra]

Hello,

I have a converyor belt. I have a spring return to center switch. To the left the conveyor belt goes one way, to the right it goes the other way. If I let go the conveyor belt stops because the switch springs back to the center off position.

This is on a control panel which control a bunch of different conveyors. Each conveyor has its own switch.

The control panel does not have an E stop.

I am thinking that the spring return to center is not enough to be compliant with NFPA 79 requirements.

Thoughts?

Did your risk assessment process determine you needed an estop?