Hi Brian:
The answers to your questions can be found here: https://www.ecmag.com/section/codes-standards/requirements-gfpe A GFPE is not to protect the PE conductor. Neither is it equivalent to a GFCI or ELCB. The requirements of when a GPFE is to be installed are spelled out in the National Electrical Code. “A ground fault is typically not a solid or “bolted fault” condition, so dynamic arcing impedance is introduced in the circuit. This reduces the fault current seen by a standard overcurrent device and increases the time the fault can exist, which allows arcing faults to manifest into destructive events. During an arc event, ionized gas is dispersed, creating a conductive gas or plasma in the atmosphere surrounding the busbars within the equipment. This condition often rapidly escalates from an initial phase-to-ground fault event to a phase-to-phase short-circuit condition. This is why the NEC requires GFPE. Sections 210.13, 215.10, 230.95, 240.13, 517.17 and others provide GFPE requirements.” >From this article, a GFPE is required on 277 volts and higher, 3-phase wye, >4-wire, rated 1000 amps or more. Best regards, Rich From: Kunde, Brian [mailto:[email protected]] Sent: Tuesday, January 30, 2018 2:04 PM To: [email protected] Subject: [PSES] GFCI vs GFPE I’ve recently come to understand that the 30mA Ground-Fault protectors, often built into a circuit breaker, is intended to protect the Protective Earth (Safety Ground) circuit in the case of a short circuit (opening the circuit before the safety ground could be damaged. It this correct? Here is my question. I’m evaluating a cut-off saw (5hp) which uses water to keep the blade and material cool. The manufacturer uses a 3-phase supplementary circuit breaker which includes the 30mA GFPE option. This is a very expensive part. When I asked them why they use the GFPE part, they couldn’t give me a good answer. Would such a part be required on a 3-phase motor driven cutoff saw in either North America or Europe? What standard would dictate this? If the only purpose of a GFPE is to protect the Ground Circuit, on products that can handle shorts without damaging the ground circuit, would a GFPE still be necessary? Where are GFPE typically used? What industry? Please educate me. This is a new one on me. Thanks, Brian - ---------------------------------------------------------------- This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at: http://www.ieee-pses.org/emc-pstc.html Attachments are not permitted but the IEEE PSES Online Communities site at http://product-compliance.oc.ieee.org/ can be used for graphics (in well-used formats), large files, etc. Website: http://www.ieee-pses.org/ Instructions: http://www.ieee-pses.org/list.html (including how to unsubscribe) List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher: <[email protected]> David Heald: <[email protected]>
