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Motor Starter Coordination -Implications -Benefits. Coordination -A practical definition:. “Selection of starter components: The short circuit protection element, (eg:Fuses/ Circuit breaker) The switching (Contactor)element The motor protection (Thermal Overload/ circuit breaker)element
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Motor Starter Coordination -Implications -Benefits
Coordination -A practical definition: “Selection of starter components: • The short circuit protection element, (eg:Fuses/ Circuit breaker) • The switching (Contactor)element • The motor protection (Thermal Overload/ circuit breaker)element ..such that the occurence of a short circuit fault will result in a predictable outcome”. However different levels of coordination will lead to different results following a short circuit fault
Type 2 coordination- Definition according to BS/EN 60947-4-1 • « Effective limitation of the fault condition with no damage resulting to the components of the motor starter other than light tack welding of contactor main contacts which can easily be broken» However: • 3 levels of coordination are considered by the standards • Type 1 coordination to BS EN 60947-4-1 • Type 2 coordination to BS EN 60947-4-1 • Total coordination to BS EN 60947-6-2
Allows damage to all components when confined within their enclosure Allows tack welding of main poles (easily broken) and a change of O/L characteristics Allows only tack welding of main poles (easily broken) BS/EN 60947-4-1 minimum requirements: Type 1 coordination Type 2 coordination
Type 1 coordination -minimum performance required following a short circuit fault: • Damage to / destruction of starter components is acceptable, but there must be: • No danger to personnel eg: ejection of damaged components from the enclosure (Note risk if panel door open & panel live) • No damage to external installation, Effect of a short circuit fault: Downtime to replace components/ rebuild starter will be significant
Type 2 coordination- minimum performance required after a short circuit • Weld of contactor main contacts acceptable, provided weld is easily broken, and there must be: • No damage to the installation • No danger to personnel • No need to replace components Effect of a short circuit fault: Downtime reduced, compared to type 1 coordination Checking contactor main pole contacts ( breaking tack welds if necessary) & replacing fuse links where used is required
To achieve type 2 coordination selection of the correct components is vital!Proven Type 2 coordination is the minimum requirement to ensure safety- But technology has moved on…….. Total coordinationis now a practical possibility
Requirements for Total Coordinationfor compliance with BS EN 60947-6-2 • Starter must be a CPS (Control and Protective Switching) device. • No damage to starter assembly acceptable • Ongoing electrical life must be guaranteed • No damage to the installation acceptable • No danger to personnel acceptable • Equipment may immediately be reset and restarted, once short circuit fault removed Effect of a short circuit fault: Minimal downtime. -Removal of fault followed by resetting and restarting of equipment is all that is necessary
Telemecanique independently certified CPS Motor starters withTotal coordination Single product solution • TeSys model U up to 32A Single product solution with diagnostics • Tesys model U with Multi- function module Single product solutions with AS-I capability • Tesys model U with AS-i module Single product solutions with diagnostics and full communications capabiilty • Tesys model U with Multifunction module and Modbus or Canbus coms module
Tesys model U provides unique benefits enabling maximisation of machine uptime • Total coordination • Minimum downtime following fault • No damage to installation following a fault • No reduction in service life • Easier selection of correct components to ensure integrity of the installation • Diagnostics capability- Retention and downloading of data: • Last 5 trip occurences • Reason for trip- (short circuit or thermal) • Total no hours run • No of operations
Summary • Effective coordination of starter components is essential forsafety and minimum downtime following a short circuit fault • Type 1 coordination must be considered unacceptable for all but the simplest installations where downtime in the event of a fault is not critical • Type 2coordination can reduce downtime in the event of a short circuit fault, but requires careful selection of components • Totalcoordination virtually eliminates downtime due to short circuit faults. Selection of a CPS device is simple