i have a simplex tech that wants me to re pull a 2 cond non shielded in place of the 2 cond shielded i allready have pulled 19 flrs up & dn loop he says he needs a non shielded . i have a shielded pulled if he does not connect the shield or drain wire what does it matter the cable is just for audio on a new simplex mapp net system larry
fire alarm
- Thread starter yorkie
- Start date
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Re: fire alarm
I have made that work in the past. have to cut and tape over all of the sheild splices in every box, as if there is no shield, and make sure that the shield does not accidently ground anywhere.
some of the newer systems are not even using twisted pair for notification.
I have made that work in the past. have to cut and tape over all of the sheild splices in every box, as if there is no shield, and make sure that the shield does not accidently ground anywhere.
some of the newer systems are not even using twisted pair for notification.
ron
Senior Member
- Location
- New York, 40.7514,-73.9925
Re: fire alarm
The shield may acts like an antenna.
The shield may acts like an antenna.
jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: fire alarm
If its audio i would think grounding a shield would be better.What is the impedance of his equipment ? if high that might be the problem
If its audio i would think grounding a shield would be better.What is the impedance of his equipment ? if high that might be the problem
Re: fire alarm
Is this a young simplex tech? They tend to hire young guys at slave wages, train them (barely) and then unleash them on unsuspecting clients.
Shielded cable is far superior to non-shielded...just ground the shield at one point only.
Shielded cable is used to minimize RF in speaker cables when there is close proximity to such a source (FM transmitter, etc).
If you can't work with this guy, I suggest you contact the manager at your Simplex field office and see if he has an 'old' tech who can help set things straight.
Trouble is, the 'old' techs are working for Siemens or Notifier or someone who appreciates their abilities and pays them accordingly.
Is this a young simplex tech? They tend to hire young guys at slave wages, train them (barely) and then unleash them on unsuspecting clients.
Shielded cable is far superior to non-shielded...just ground the shield at one point only.
Shielded cable is used to minimize RF in speaker cables when there is close proximity to such a source (FM transmitter, etc).
If you can't work with this guy, I suggest you contact the manager at your Simplex field office and see if he has an 'old' tech who can help set things straight.
Trouble is, the 'old' techs are working for Siemens or Notifier or someone who appreciates their abilities and pays them accordingly.
TOMWELDS
Member
- Location
- Westchester Cty. New York
Re: fire alarm
If the wire is feeding a speaker, i'd say, non shielded. If it's going to an amplifier, then shielded.
If the wire is feeding a speaker, i'd say, non shielded. If it's going to an amplifier, then shielded.
Re: fire alarm
I asked my fire alarm goo roo, so i have no code reference, but he said that a sheilded cable with shieleds cut at both ends should act as an unsheilded cable with no adverse effects, but that he would have to look it up to see if this were infact a code violation.
Most newer systems are calling out un-shielded cable for the notification circuit (speaker/strob/relay modules). In fact some dont even call for twisted pair, THHN is being used.
I asked my fire alarm goo roo, so i have no code reference, but he said that a sheilded cable with shieleds cut at both ends should act as an unsheilded cable with no adverse effects, but that he would have to look it up to see if this were infact a code violation.
- Location
- Massachusetts
Re: fire alarm
What where you instructed to pull?
The last Simplex system I did specified unshielded for the speakers and shielded for the strobes. Seemed backward to me but what matters is doing what you are hired to do.
If you are going to install fire alarm systems you must check the manufactures cable / condutor requirements first or you may be working for free.
In my opinion this is the best answer given so far.
What where you instructed to pull?
The last Simplex system I did specified unshielded for the speakers and shielded for the strobes. Seemed backward to me but what matters is doing what you are hired to do.
If you are going to install fire alarm systems you must check the manufactures cable / condutor requirements first or you may be working for free.
Re: fire alarm
I need to correct myself. I talked to my workers. we used shielded for the speakers, and THHN for the strobes, and unsheilded for the pull stations.Originally posted by iwire:
The last Simplex system I did specified unshielded for the speakers and shielded for the strobes. Seemed backward to me but what matters is doing what you are hired to do.
- Location
- Massachusetts
Re: fire alarm
JB That was on one particular Simplex system.
As far as I know another model Simplex may use fishing line and kite string.
Each FA job I am involved in we get the specific conductor info from the manufacturer before we go to far.
There are just to many types to guess what they want twisted, not twisted, shielded, not shielded, metal raceway or low energy cable.
That System I described specified using the following cables in metal raceway.
Detectors - Twisted Shielded.
Strobes - Twisted Shielded
Speakers - Twisted
JB That was on one particular Simplex system.
As far as I know another model Simplex may use fishing line and kite string.
Each FA job I am involved in we get the specific conductor info from the manufacturer before we go to far.
There are just to many types to guess what they want twisted, not twisted, shielded, not shielded, metal raceway or low energy cable.
That System I described specified using the following cables in metal raceway.
Detectors - Twisted Shielded.
Strobes - Twisted Shielded
Speakers - Twisted
- Location
- Massachusetts
Re: fire alarm
I did not take it like you where correcting me, I just did not want you to change what you do based on my past experience with Simplex.Originally posted by jbwhite:
iwire, I was correcting myself not you.
dnbob
Senior Member
- Location
- Rochester, MN
Re: fire alarm
We use a lot of Simplex 4010 panels, and we are always required to pull twisted shielded cable for all pull stations, smokes, heats & iams. etc.
The horn circuits are 14-2 non shileded or else #14 thhn if in conduit.
Bob
We use a lot of Simplex 4010 panels, and we are always required to pull twisted shielded cable for all pull stations, smokes, heats & iams. etc.
The horn circuits are 14-2 non shileded or else #14 thhn if in conduit.
Bob
peter d
Senior Member
- Location
- New England
Re: fire alarm
Shame on you Bob. If you read your specs carefully, you would see they call for wet kite string.
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