Operation With Switch-Mode Power Supplies; Effect Of Frequency; Response Time; Input Characteristics - Sola HD MCR Portable Série Mode D'emploi

6.5 operation with Switch-Mode Power Supplies

If an MCR is used as a source for a switch-mode power supply, a slight amount of ringing may be noticed on the sine wave
output of the unit at half cycle intervals for a short duration. This ringing occurs at the point when the switch-mode power supply
current demand drops to zero. The ringing need not be a cause for concern since it is of relatively low magnitude and frequency.
Both series have been tested with a variety of switch-mode power supplies and it has been determined that the ringing does not
affect the dc outputs, nor has it been found to degrade the components of any switch-mode power supply.

6.6 effect of Frequency

Changes in the frequency of the supply voltage will be directly reflected in the output voltage. A change of about 1.8% in output
voltage will occur for every 1% change in input frequency, and in the same direction as the frequency change.

6.7 response time

An important advantage of the SolaHD principle of static magnetic regulation is its exceedingly fast response time compared
with other types of ac regulators. Transient changes in supply voltage are usually corrected with 1-1/2 cycles or less; the output
voltage will not fluctuate more than a few percent.

6.8 input Characteristics

The MCR's transformer includes a resonant circuit, which is energized whether it is serving a load or not. Therefore, the input
current at no load is approximately 35% of the full-load level, even at light or no load. Input power factor will average 90–100% at
full load, but may drop to about 75% at half load and 25% at no load. In any case, it is always leading.

6.9 Current Limitations

When the load is increased beyond the MCR's rated value, a point is reached where the output voltage suddenly collapses and
will not regain its normal value until the load is partially released. Under short-circuit conditions, the load current is limited to
approximately twice of the rated full-load value, and the input power to less than 10% of normal. The unit will protect both itself
and its load against damage from excessive fault currents. Fusing of load circuits is not necessary.

6.10 operation with Motor Loads

Because of the current-limiting effect described above, special attention should be given to motor applications. In general, the
regulator must have a load rating nearly equal to the maximum power drawn during the starting cycle. This may run from two to
eight times the normal (running) rating of the motor. In doubtful cases, it is advisable to measure the actual starting current.
7.0 Service & Maintenance
7.1 Service & Maintenance
The unit is a simple, rugged device with no moving parts. Routine service and/or maintenance is not required. If a problem does
occur, please refer to "8.0 Troubleshooting" or contact SolaHD Technical Support for assistance.

7.2 Field replacement of Capacitors

Capacitors used in our units are the highest commercial grade, with each one given a rigid acceptance test upon receipt. SolaHD
guarantees free replacement of any capacitors which fail within one year of sale. Older units can be replaced at a moderate
charge.
nOTE: It may be possible to test and identify defective capacitors in the field. Please contact SolaHD Technical Support at
1.800.377.4384 or 1.847.268.6651 for further assistance.
MCR PORTABLE SERIES USER MAnUAL | 7