Re: [PSES] External toothed star washer used in earth connection

… a star washer was not acceptable for military grounding. The rationale was that the points of the star washer created the conductive grounding path. Since the points were fairly small, and the ground fault current was high, a fault current would be forced to flow across those tiny

Re: [PSES] External toothed star washer used in earth connection

Ted's reference to the Ingalls study includes proposed changes to MIL-STD-1310. Furthermore: "It is recommended that the use of grounding washers in place of cleaning to “Bright Metal”..." Best regards, Rich -Original Message- From: Brian O'Connell Sent: Friday, August 10, 2018

Re: [PSES] External toothed star washer used in earth connection

The rationale was that the points of the star washer created the conductive grounding path. Since the points were fairly small, and the ground fault current was high, a fault current would be forced to flow across those tiny point-contacts. This had the danger of causing the points to

Re: [PSES] External toothed star washer used in earth connection

MIL-B-5087 is superseded by MIL-STD-464, which says "Overpainting of structure for corrosion control prior to ensuring an electrical bond has been documented as the leading cause of poor or ineffective bonds." MIL-STD-464 points to MIL-STD-1541 - for space systems ARP187 - electrical

Re: [PSES] External toothed star washer used in earth connection

I seem to recall seeing an explanation in MIL-B-5087 (likely now superseded) that a star washer was not acceptable for military grounding. The rationale was that the points of the star washer created the conductive grounding path. Since the points were fairly small, and the ground fault current

Re: [PSES] LVD votlage scope query

The wording of Article 1 of the Directive has always been suspect. 'designed for use with a voltage rating' is not wording that any electrical engineer would use, and really has no good interpretation. 'designed with a voltage rating' would be OK, but actually 'designed' is superfluous. But

Re: [PSES] LVD votlage scope query

Thanks Scott. The last sentence makes it very clear. *"For products with multiple voltage ratings, input or output, the products are considered within the scope of this Directive as soon as one of the ratings fall within the given voltage rating."* Regan On Fri, Aug 10, 2018 at 2:55 PM, Scott

Re: [PSES] X & Y Cap rating due to hipot test

Hi Ken: Line-to-ground, yes. Line-to-line, no. If the caps are certified, they are at least good for 1500 volts rms. Best regards, Rich From: Ken Javor Sent: Friday, August 10, 2018 11:44 AM To: EMC-PSTC@LISTSERV.IEEE.ORG Subject: [PSES] X & Y Cap rating due to hipot

Re: [PSES] LVD votlage scope query

Hi Regan, See the LVD guidelines , section 6. From the guide: "The Directive applies to all electrical equipment 8 designed for use with a voltage rating of between 50 and 1000 V for alternating current and between 75 and 1500 V for direct current.

[PSES] LVD votlage scope query

Hi folks. It's been a while since I went on the europa website and I just saw this (never noticed it before). The general europa webpage section of the LVD has bolded the text " *input* *or* *output voltage* ". More interestingly, the conjunction ‘*or*’. Some could now argue that their HV power

Re: [PSES] External toothed star washer used in earth connection

Hi Scott: For the sake of this discussion, a toothed star lock washer has two functions: (1) keep the bolt from loosening, and (2) establishing a “good” electrical connection. (One characteristic of a good and reliable electrical connection is that the contact between the two conductors

Re: [PSES] X & Y Cap rating due to hipot test

Thank you, Ken Javor Phone: (256) 650-5261 From: Doug Powell Reply-To: Doug Powell Date: Fri, 10 Aug 2018 13:41:40 -0600 To: Subject: Re: [PSES] X & Y Cap rating due to hipot test Ken, Yes and No, the line to line "X" caps will not see hipot potentials since you should tie lines and

Re: [PSES] X & Y Cap rating due to hipot test

Ken,Yes and No, the line to line "X" caps will not see hipot potentials since you should tie lines and neutral together during the test.  Line to earth "Y” caps will see the entire voltage during the test.  This assumes of course you have manually closed any circuit breakers, contractors or

[PSES] X & Y Cap rating due to hipot test

Does a 1000 V insulation resistance test requirement force line-connected caps to the high pot potential? Thank you, Ken Javor Phone: (256) 650-5261 - This message is from the IEEE Product Safety Engineering Society emc-pstc

Re: [PSES] External toothed star washer used in earth connection

Hi Rich, Thanks for your advice!  Regarding the flat washer, can it be the flat ring lug of the connecting wire instead? Between the screw head and the metal enclosure, do we need a flat washer? That is to say: screw head -> flat washer -> metal enclosure -> on other side of metal