Heatcraft Refrigeration Products Air-Cooled Condensers none - Manual (Page 17)

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Master/Slave Configuration
The.EC.motor.control.signals.are.wired.in.a.Master/
Slave.configuration ...This.configuration.allows.for.the.
maximum.sound.and.energy.reduction.as.well.as.the.
most.stable.head.pressure.control ...The.control.signal.is.
delivered.to.the.master.motor.(located.at.the.header.end.
of.the.unit) ...The.master.motor.relays.the.control.signal.to.
the.adjacent.slave.motor ...This.relay.is.done.until.the.last.
motor.is.reached ...As.each.slave.relays.the.control.signal,.
it.adjusts.the.signal.so.the.next.slave.will.run.slightly.
slower.than.the.upstream.motor ...The.end.result.of.this.is.
that.when.a.motor.receives.a.small.enough.signal,.it.will.
turn.off ...This.provides.built-in.fan.cycling .
Protective Features
The.EC.motors.have.many.built-in.protective.features .
The.EC.motors.have.functions.within.the.motor.to.
protect.against:
•.over-temperature.of.electronics
•.over-temperature.of.motor
•.incorrect.rotor.position.detection
With.any.of.these.failures,.the.motor.stops.electronically.
and.the.alarm.relay.is.switched ...With.one.of.these.
failures,.the..motor.WILL.NOT.automatically.restart ...To.
reset,.the.power.supply.has.to.be.switched.off.for.a.
minimum.20.seconds.once.the.motor.is.at.standstill .
Locked-rotor protection
As.soon.as.the.rotor.is.blocked,.the.motor.gets.switched.
off.electronically.and.the.alarm.relay.is.switched ..After.
de-blocking,.the.motor.WILL.restart.automatically .
Under-voltage protection
If.power.supply.voltage.falls.below.~150VAC/3Ø.(for.230V.
motors).or.~290VAC/3Ø.(for.460V.motors).for.5.seconds.
minimum,.the.motor.will.be.switched.off.electronically.
and.the.alarm.relay.is.switched ...If.power.supply.
voltage.returns.to.correct.values,.the.motor.WILL.restart.
automatically .
Phase failure
If.1.phase.fails.for.5.seconds.minimum,.the.motor.will.
be.switched.off.electronically.and.the.alarm.relay.is.
switched ...If.all.3.phases.return.to.correct.values,.the.
motor.WILL.restart.automatically.within.10-40.seconds .
EC Motor Wiring
All.EC.motor.wiring.is.done.at.the.factory ...If.any.motor.
wiring.needs.to.be.done.in.the.field,.the.diagram.below.
indicates.the.terminal.pin.configurations.inside.the.
motor.junction.box ..Terminals.in.shaded.area.are.not.
normally.used .
The.following.diagram.shows.typical.motor.wiring.for.a.1.
x.4.EC.condenser .