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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 devicesApower 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.