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3-14 BasicInstallation MN1942

3.4.3.3 Supplying input pow er from a variac (variable transformer)
When AC power is supplied from a variac, the MicroFlex e100’s pre-chargec ircuit may not
operatecorrec tly.To ensure that the pr e-charge circuitry operates correctly,increase the variac
voltagetothedesired leveland thenpower cycle the24VDC controlcircuit supply.This willrestart
thepre -charge circuit and allow it to operate correctly.
3.4.4 Pow erd isconnect and protection devices
Apower disc onnect should be installed between the input power supply and the MicroFlex e100
for a fail-safe method to disconnect power. The MicroFlex e100 will remain in a powered
conditionuntil all input power is removedfrom the driv e and the internal bus voltage hasdepleted.
TheMic roFlex e100 must have a suitable input power protection device installed, preferably a
fuse. R ecommended circuit breakers are thermal magnetic devic es (1 or 3 phase as required)
withcharacteris tics suitable for heavy induct ive loads (C-type trip charac teristic). Circuit br eaker
orfus es are not supplied - see section 3.4.5. For CE c ompliance, see Appendix C.
CircuitBreaker
L
N
From
supply
L
N
From
supply
Fuse
L
N
L
N
Figure4 - Circuit breaker and fuse, single-phase
CircuitBreaker
Circuitbreaker or fuse are not supplied.
ForCE Compliance, see Appendix C.
L1
From
supply
Fuses
L2
L3
L1
L2
L3
From
supply
L1
L2
L3
Figure5 - Circuit breaker and fuse, three-phase
Note: Metalconduit or s hielded cable should be used. Connect conduits so the use of a
linereactor or RC device does not interrupt EMI/RFI shielding.
3.4.4.1 Using 2 phases of a 3-phase supply
Powermay be derived by connecting two phas es of an appropriate three-phase supply (L1and
L2for example). When supplying AC powerin this way, the voltagebetween the two phas es must
notex ceed the rated input voltage of the MicroFlex e100. A two pole break er must be used to
isolateboth lines . Fuses must be fitted in both lines.