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Seismic Requirements for electrical equipment based on weight limit

Seismic Requirements for electrical equipment based on weight limit

(OP)
A number of fire panel manufactures have had their equipment tested for OSHPD seismic certification per-approval. In discussions with one manufacture, I was told that if the equipment weighs less than X pounds (20 lbs is what the person thought the value was), seismic calculations aren't required. He sighted smoke detectors as an example.

I has asked were he was getting the weight limit from as I don't see it is ASCE 7-10 (2010 edition), Chapter 13.

Can someone give me some guidance related to this?

I see Section 13.1.4 "Exemptions", has section 6.c.ii. which requires "...all of the following apply:"
  1. ...importance factor of 1 (fire protection has a 1.5 importance factor)
  2. ...positively attached (not sure what that actually means).
  3. Flexible connections between component...and...
    1. ...componet weighs 400
    2. ...component weighs 20 lb or less (89 N) or less or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.
The device in question is an "Air Sampling Smoke Detector" that is mounted on a sheet rock wall more than 4' above the floor and weighs less than 20 lbs.

Is there some other escape clause I should be looking at?




Regards,
DM

"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."

RE: Seismic Requirements for electrical equipment based on weight limit

For OSHPD, see 2016 CBC section 1616A.1.18 for modifications to ASCE 7. The CBC chapter 16A requirements are similar to ASCE 7 but doesn't require Ip =1.

RE: Seismic Requirements for electrical equipment based on weight limit

(OP)
WannabeSE,
Thanks for your input but unfortunately that doesn't help me in my situation. My reference to OSHPD was simply that the documents companies have published for pre-approval might help me with my customer in Texas. While Texes is zone 0, our customer has a standard that all buildings in the US have to comply with (Verizon).

I was hoping there might be something in the IBC similar to CBC but the 2015 edition of the IBC I have only goes up to 1615 (there is no 1616 so this must be a California Modification). I will have a look at CBC however and see what it says.

Regards,
DM

"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."

RE: Seismic Requirements for electrical equipment based on weight limit

I believe this was a change in the 2016 edition of ASCE 7:

13.1.4 Exemptions. The following nonstructural components
are exempt from the requirements of this chapter:

...

5. Mechanical and electrical components in Seismic Design Category C provided that either

a. The component Importance Factor, Ip, is equal to 1.0 and the component is positively attached to the structure; or

b. The component weighs 20 lb (89 N) or less
or, in the case of a distributed system, 5 lb/ft (73 N/m) or less.

6. Discrete mechanical and electrical components in Seismic Design Categories D, E, or F that are positively attached to the structure, provided that either

a. The component weighs 400 lb (1,779 N) or less, the center of mass is located 4 ft (1.22 m) or less above the adjacent floor level, flexible connections are provided between the component and associated ductwork, piping, and conduit, and the component Importance Factor, Ip, is equal to 1.0; or

b. The component weighs 20 lb(89 N)or less
or, in the case of a distributed system, 5 lb/ft (73 N/m) or less;

RE: Seismic Requirements for electrical equipment based on weight limit

(OP)
You guy's have to forgive me as this is the first time I've had to deal with seismic requirements.

The problem with 13.1.4.6 is the "...all..." requirement and the importance factor of 1, where as fire protection equipment is a 1.5.

Section 13.1.4.4, may be applicable (Design Category B) as it isn't concerned with the Ip and the design catagory for my project is "A". Am I missing something?

Regards,
DM

"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."

RE: Seismic Requirements for electrical equipment based on weight limit

The key word that removes the Importance Factor from consideration is the "or" at the end of 5a and 6a. At least that's how I interpret it.

I had assumed you were in a higher seismic region. If you are SDC A, then Section 11.7 states, "Nonstructural components in SDC A are exempt from seismic design requirements."

RE: Seismic Requirements for electrical equipment based on weight limit

(OP)
Bones206...Your reference to 11.7 would seem to be my escape clause.

One thing I just noticed is that the spec's reference ASCE 7-10, section 9, which is "Reserved For Future Provisions". I'm new to ASCE so I'm guessing "7-10" refers to the 2010 edition? I also had a look at 7-16, which seems to apply to the 2016 edition?

Regards,
DM

"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."

RE: Seismic Requirements for electrical equipment based on weight limit

Yes ASCE 7-10 is the 2010 edition. That edition is invoked by reference through IBC 2012.

We are running into these issues quite often in my office, as electrical and mechanical engineers unfamiliar with ASCE 7 are having to provide and interpret seismic requirements for their components and systems.

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