Inrush Current - ETC Prodigy, FlyPipe, and Vortek NXT Hoists
Inrush Current
ETC is commonly asked how to take inrush current into account when sizing breakers for hoist installation. Fixed speed hoists have a momentary high inrush current as the motor starts moving and the higher inrush current needs to be taken into account when powering a hoist.
Example: A Prodigy P1300G 208V hoist has a current draw of 6.5A while operating, but a momentary inrush current around 16.8A.
The boiler plate language is that ETC Prodigy and Vortek hoists required 208V, 60 Hz, 3-phase power and/or 480V, 60 Hz, 3-phase power service installed and sized according to NEC 430, Motors, Motor Circuits, and Controllers.
Generally ETC recommends that breakers are sized for the operating current of the hoist and that power for ETC hoists is provided from a breaker with a D Trip Curve.
The trip curve of the breaker determines how quickly the breaker will trip in an overcurrent condition. A D curve breaker is designed to allow the momentary inrush current from the hoist when it starts moving, momentarily allowing 10-15 times the rated current . If a C or B curve breaker is used to supply power to ETC hoists nuisance tripping of the breaker may become an issue.
Example: Two Prodigy P1300G 208V hoists can be powered by a single 20A D curve breaker.
20A Breaker capacity (80% Rated Breaker) = 16A
Prodigy P1300G current draw @ 208V = 6.5A * 2 = 13.0A
ETC Power & Control Distribution (PCD)
ETC Power and Control Distribution (PCD) faceplates use a 15A breaker for all standard 208V hoist applications and a 16A breaker for all standard 480V hoist applications.
PCD main-fed raceways are rated for a 170A maximum input feed and discrete fed raceways are rated for a 30A maximum circuit input.
ETC recommends a maximum power feed into individual PCD distribution boxes of 20A.
Additional Power & Control Distribution Power Information can be found here: Power Feed Requirements - Power and Control Distribution
ETC Hoist Power Information
For reference, power information for ETC hoists can found on the notes page of the submittal drawing set and in the chart below.
