Safety switches/local isolator Switches NEAR ELECTRIC MOTORS

J

Joao

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Location
portugal
Occupation
engineer
Is not usually to install NEAR each electric motor a safety local switch.

May be for special case like conveyors or similar.

In case that we have for example 1000 electric motors are needed apart of CB install upstream a local switch device?

Any IEC standard with that OBLIGATION?

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No idea about the IEC, but the general rule in the NEC is that a disconnect be provided within sight of each motor. There is an exception for industrial applications that permits remote lockable disconnect. 430.102
 
don_resqcapt19 said:
No idea about the IEC, but the general rule in the NEC is that a disconnect be provided within sight of each motor. There is an exception for industrial applications that permits remote lockable disconnect. 430.102
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So it means that for industrial/power plants is not MANDATORY to have it correct? Because if we have for example 1000 electric motors I want to believe that all otors do not need that device. May be a risk assessement shall be done and evaluate it. Do you agree?
 
Joao said:
So it means that for industrial/power plants is not MANDATORY to have it correct? Because if we have for example 1000 electric motors I want to believe that all otors do not need that device. May be a risk assessement shall be done and evaluate it. Do you agree?
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Here is the rule from the NEC. Many industrial facilities use the provisions of Exception #2. However some do install disconnects within sight of each motor.
430.102(B) Motor.
A disconnecting means shall be provided for a motor in accordance with 430.102(B)(1) or (B)(2).
(1) Separate Motor Disconnect.
A disconnecting means for the motor shall be located in sight from the motor location and the driven machinery location.

(2) Motor Controller Disconnect.
The motor controller disconnecting means required in accordance with 430.102(A) shall be permitted to serve as the disconnecting means for the motor if it is in sight from the motor location and the driven machinery location.

Exception to (1) and (2):
The disconnecting means for the motor shall not be required under either of the following conditions if the motor controller disconnecting means required in 430.102(A) is lockable in accordance with 110.25:
(1)Where such a location of the disconnecting means for the motor is impracticable or introduces additional or increased hazards to persons or property

Informational Note No. 1:
Some examples of increased or additional hazards include, but are not limited to, motors rated in excess of 100 hp, multimotor equipment, submersible motors, motors associated with adjustable-speed drives, and motors located in hazardous (classified) locations.

(2)In industrial installations, with written safety procedures, where conditions of maintenance and supervision ensure that only qualified persons service the equipment
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As far as your question about the term "within sight", the NEC says this:
110.29 In Sight From (Within Sight From, Within Sight).
Where this Code specifies that one equipment shall be “in sight from,” “within sight from,” or “within sight of” another equipment, the specified equipment shall be visible and not more than 15 m (50 ft) distant from the other.
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zbang said:
Implicit in Exception #2 is that "written safety procedures" includes lock-out/tag-out protocols where appropriate.
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It has been a very long time since I worked in an industrial facility that did not have detailed written lock-out procedures.
About 25 years ago, there was one plant where our guys were doing work at that did not have such procedures. We had to do lock out to do our work safely, and before we finished the project, the plant had us help write lock out procedures for them.
 
don_resqcapt19 said:
Here is the rule from the NEC. Many industrial facilities use the provisions of Exception #2. However some do install disconnects within sight of each motor.


As far as your question about the term "within sight", the NEC says this:
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Thanks is clear. I will chek if there is any similar IEC.
 
Joao said:
Thanks is clear. I will chek if there is any similar IEC.
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Check for safety regulations above and beyond electric codes, like the NEC which are typically for installations.

In the US a common code is NFPA 70E for maintenance and operations and OSHA for workplace regulations.
 
This forum is based in North America and is generally related to our rules here, the National Electric Code (NEC) and Canadian Electric Code (CEC). Our codes do not apply in Portugal, you really need to take this up with people in your country familiar with your requirements.

That said, I used to work for German companies and have had some exposure to IEC regulations, so I know they are very similar in these aspects. I believe that IEC 60204 is a pertinent standard for safety of machinery and requires disconnecting means near motors. There may be exceptions like there are here, but I would not assume you can ignore this.
 
don_resqcapt19 said:
It has been a very long time since I worked in an industrial facility that did not have detailed written lock-out procedures.
About 25 years ago, there was one plant where our guys were doing work at that did not have such procedures. We had to do lock out to do our work safely, and before we finished the project, the plant had us help write lock out procedures for them.
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Smaller facilities or at least a facility not controlled by a fairly large company you might still run into lack of such procedures.

I have run into cases with smaller family run organizations that started to comply more with some OSHA requirements of any aspect, not just LOTO, because their insurance provider pushed these safety issues. They still not as involved with a fairly detailed safety department like larger corporations often are though.
 
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