My understanding of these definitions (per IEC 60947-2):
Sometimes the IEC ratings are printed on the ABB breaker in addition to UL for breakers sold in the USA. The ABB Tmax XT product line is however a global breaker and meets both IEC and UL standards. These terms are part of the IEC standard so they don’t apply to UL-489 listed breakers. In cases where neutral protection settings differ from phase, I suggest copying the breaker and pasting it directly in series then use this breaker for the neutral settings and curve plot.Ĭan you explain the difference between Icu, Ics, Icw which are written on the label of MCCB? Typically, the neutral protection is set to match the phase overcurrent settings so there would be no need for a separate neutral curve. In the time current curves of MCCB's can we see neutral protection curves?ĮasyPower does not include separate settings for neutral overcurrent protection in molded case or power circuit breakers. On ABB Ekip Touch trip units, the neutral overcurrent protection can be set to 50%, 100%, 150%, or 200% of the phase overcurrent settings. The breaker also includes neutral overcurrent protection.
For a 4-wire system, an external neutral CT is installed and the ground fault current is measured by summing current vectors A,B,C,N.Ī 4-pole breaker always measures ground fault current by the sum of A,B,C,N. For a 3-wire system, ground fault current is measured by summing phase current vectors A,B,C. What is the difference between a 3-pole LSIG breaker and 4-pole LSIG breaker?Ī 3-pole LSIG breaker can be applied to either a 3 wire (no neutral) or a 4 wire (solid neutral) system. Primary injection testing is typically performed on all trip unit retrofit breakers to ensure proper operation. The UL product category PAYK certification covers the retrofit trip only and not the breaker onto which it is installed. Can the trip unit be replaced on a UL listed breaker without type testing?ĪBB trip unit conversion kits are design verification tested to ANSI C37.59 but do not carry a UL certification mark. Please discuss listing of breakers that have been retrofitted with a trip unit. Yes, ABB manufactures a retrofit kit to install new Tmax XT breakers into existing Spectra bolt-on panels. will an XT breaker fit in a Spectra panel. The Bluetooth communication option available in Ekip Touch trip units is useful for this situation as the operator can stay clear of the arc-flash distance while changing the breaker settings.Īre the XT breakers compatible with older GE Spectra panels, i.e. Care must be taken because if the new setting is lower then the load, the breaker will trip.
Setting adjustments can be made while the breaker is energized, closed, and within rated load. Answers to Q&A Following Live Webinar QuestionĬan these breakers TCC settings be adjusted while on-line or will an outage need to occur?
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