120v versus 125v

[ice2aqua]

What is the differance between having 125v on the drawing, and 120v on the product?

 

[jobeth]

5 volts..............Ha Ha <p>William H. Bernhart, P.E.<br><a href=mailto: > </a><br><a href= > </a><br>I work as a development engineer for AMP - Tyco Electronics located near Harrisburg, PA. I help design interconnections and electrical connectors for aerospace applications.

 

[navam]

ice2aqua, I am afraid your question makes no sense to me.&nbsp;&nbsp;Can you elaborate, please?&nbsp;&nbsp;What is the drawing, what is the product, what do the voltages refer to, and what is the relationship between the drawing and the product?

 

[dbaird]

It could mean the difference in gaining acceptance/approvals from the customer and/or testing agencies. For instance, NFPA 79 qualifies equipment to operate at +/- 10% of &quot;rated voltage&quot;. Consequently the extra 5 volts in question could pass or fail you in this instance. This qualification is given due to the fact utility line voltages may fluctuate during peak usage but equipment must keep on operating satisfactorily. The &quot;nominal&quot; USA single phase voltage is 115 VAC @ 60 Hz. <p>David Baird<br><a href=mailto:dbaird@gemcity.com>dbaird@gemcity.com</a><br><a href= > </a><br>EET degree.<br>
Journeyman Electrician.

 

[umn]

I also feel the same as David.<br><br>In the drawing, you need to consider the expected worst case. In this case, you expect 125 V. On the product, you put a buffer, and say it's 120 V max, where the nominal voltage is 110 or 115 V.<br><br>Citing another example, as per rules, any pressurized container should be capable of withstanding upto 7 times the nominal(normal operating) pressure. Type manufacturers design it for 10 times the nominal pressure! <p>Narayanan UM<br><a href=mailto:umn@ieee.org>umn@ieee.org</a><br><a href= > </a><br>

 

[jbartos]

An ideal case is to have the drawing and product voltages to agree. If there is a discrepancy, then it depends on a case. In some cases, it makes no difference, in others it does. The product 120 V should not be maximum allowed voltage or with the upper voltage tolerance smaller than 125 V. Also, drawing may indicate &quot;system voltages&quot; which are typically higher than equipment rated voltages. This is the case for many electrical motors.