Some dimensions for typical sizes of knockouts: Nominal Size of Conduit Knockout Diameter
1/2 0.859 / 0.906 3/4 1.094 / 1.141 1 1.359 / 1.406 1 1/4 1.719 / 1.766 A source of the data is NEMA ICS 6. Bill Lawrence - Factory Mutual Research At 09:06 10/07/1999 -0400, Lacey,Scott wrote: > >Jim, >I took a few quick measurements of workboxes, isolation transformers, etc. >in the lab, as well as the knockout openings in the cast housings of some of >our flow transmitters. >7/8" and 1 1/8" seem to be the most common for the smaller circuits, with 2 >3/8" and 2 3/4" used for the heavier stuff. Check a Hubbell catalog for >required sizes for cable grips, etc. > >Scott Lacey > > -----Original Message----- > From: Jim Eichner [SMTP:[email protected]] > Sent: Wednesday, October 06, 1999 5:49 PM > To: 'EMC-PSTC - forum' > Subject: RE: EN60950 - conduit entry dimensions > > > I have received very little response to this one, so I thought I'd >post > it again. > > Aren't there any permanently connected ITE equipment mfr's on this > forum?! What do you provide in the way of knockouts or ...??? > > Thanks, > > > Jim Eichner > > Senior Regulatory Compliance Engineer > Statpower Technologies Corporation > [email protected] > http://www.statpower.com > Any opinions expressed are those of my invisible friend, who really > exists. Honest. > > > > -----Original Message----- > > From: Jim Eichner [SMTP:[email protected]] > > Sent: Thursday, September 23, 1999 10:49 AM > > To: 'EMC-PSTC - forum' > > Subject: EN60950 - conduit entry dimensions > > > > > > Greetings all: In clause 3.2.2 allows the provision of knockouts, > > cable > > entries, etc. in lieu of a non-detachable power cord for >permanently > > connected equipment. In Table 10, it lists the overall diameter >of > > conduit based on the number of conductors involved, up to 16A. > > > > In my particular application, there are 2 wires plus earth, and >the > > current (and the branch circuit protection) is less than 16A, so >the > > table tells me I need a knockout that can accommodate a 16.0mm >O.D. > > conduit. If things are done there anything like they are done >here, > > this 16mm conduit will be secured in a fitting of some sort, and >the > > knockout needs to be matched to the fitting, not the conduit (i.e. >a > > 16mm hole is likely too small). > > > > Is there a reference, or can anyone tell me, what the appropriate > > sized > > hole will be? Is this standardized somewhere? > > > > Thanks in advance for your help, > > > > > > Jim Eichner > > > Senior Regulatory Compliance Engineer > > Statpower Technologies Corporation > > [email protected] > > http://www.statpower.com > > Any opinions expressed are those of my invisible friend, who >really > > exists. Honest. > > > > > > --------- > > This message is coming from the emc-pstc discussion list. > > To cancel your subscription, send mail to [email protected] > > with the single line: "unsubscribe emc-pstc" (without the > > quotes). For help, send mail to [email protected], > > [email protected], [email protected], or > > [email protected] (the list administrators). > > > > --------- > This message is coming from the emc-pstc discussion list. > To cancel your subscription, send mail to [email protected] > with the single line: "unsubscribe emc-pstc" (without the > quotes). For help, send mail to [email protected], > [email protected], [email protected], or > [email protected] (the list administrators). > > >--------- >This message is coming from the emc-pstc discussion list. >To cancel your subscription, send mail to [email protected] >with the single line: "unsubscribe emc-pstc" (without the >quotes). For help, send mail to [email protected], >[email protected], [email protected], or >[email protected] (the list administrators). > > > Bill Lawrence South Yarmouth, MA 02664 [email protected] --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
