Xylem IM244R04 SPD Plus Variable Speed Pump Control - Manual (Page 15)

15
WARNING
Hazardous
voltage
WARNING
Hazardous
voltage
OPEN DELTA (CONSULT FACTORY)
This type of configuration is common on 230 volt
systems. From time to time it may be encountered
where only single phase power is available and
three-phase power is required. The technique uses
two single phase transformers to derive a third phase.
When used to power a drive this configuration must
be derated to about 70% of the single phase rating of
one transformer. This system provides poor regulation
and it is possible that only the two line connected
phases will provide power. In this case the drive must
be derated to 50 % of its rating. (Ex. A 20 HP 230 volt
drive now becomes a 10 HP 230 volt drive.)
WARNING
“Open Delta” power systems should
be sized using the 50% derate factor.
Consult factory.
SINGLE PHASE CONNECTION
For drives with a diode rectifier front end it is possible
to run a three phase output with a single phase input.
Only part of the three phase input bridge is used.
Ripple current becomes 120 Hz rather than 360. This
places a greater demand on the DC filter components
(capacitor bank and DC choke). The result is that the
drive must be derated to 50% current. Single phase
will not work with an SCR front end drive.
LINE TRANSFORMER
The line input voltage and transformer power must
meet certain phase and balance requirements. If
you or your installing electrical contractor is in
doubt of the requirements, the following provide
guidelines for the SPD Plus installation. When in
doubt contact the local power utility or the factory.
If an isolation transformer is used, the best choice is
ONE three phase, six winding transformer. A delta
primary is best for third harmonic cancellation. A wye
secondary avoids circulating current problems and
provides the very desirable option of grounding the
secondary neutral for minimum voltage stress and
ripple to ground. The transformer should have a KVA
rating at least 1.1 times the maximum connected HP.
A K factor of 6 is sufficient if transformer impedance
is greater than 2%. A K Factor of 5 is sufficient if
transformer impedance is greater than 3%. The
transformer manufacturer may provide derating for
non K Factor rated transformers to operate at the
drive produced K Factor levels.
Other transformer configurations are acceptable.
Three single phase transformers can be used if
they are identical for phase to phase symmetry and
balance. A wye connected primary neutral should
never be grounded. Great care should be taken with
delta primary delta secondary configurations. Any lack
of phase to phase symmetry could result in circulating
currents and unacceptable transformer heating.
WARNING
Never use phase converters with drives
as nuisance tripping and possible
damage may occur. Instead, use single
phase input power and 50% derate factor.
INPUT POWER SPECIFICATIONS
Input Power (mains) Connection Specifications
208/220/230/240 VAC 3-phase or 1-phase – 15% …+10% for SPD2XXXX
Voltage (U
1
) 380/400/415/440/460/480 VAC 3-phase -15%...+10% for SPD4XXXX
500/525/575/600 VAC 3-phase -15%....+10% for SPD5XXXX
Prospective Short- Maximum allowed prospective short-circuit current in the supply is 100 kA
Circuit Current providing that the input power cable of the drive is protected with
(IEC 629) appropriate fuses. US: 100 000 AIC.
Frequency 48…63 Hz
Imbalance Maximum ±3% of nominal phase to phase input voltage
Fundamental Power 0.98 (at nominal load)
Factor (cos phi
1
)