Hitachi EC702MP-BB3 Operation Manual page 16

Recommendations
1. We recommend that the transmitter "never see" the power grid directly.
2. We recommend the use of online double-conversion UPS and / or Delta-
conversion online UPS built with transformer insulation and with power
factor correction (PFC).
Benefits:
These types of UPS bring great protection and insulation to the transmitter due to its design.
The double conversion occurs because the AC network converts to DC and the DC voltage
converts back to AC, which eliminates any disturbance in the AC mains when converted to
DC, thus protecting the transmitter.
It is important to note that UPS's do not necessarily need to have a battery bank, thus
minimizing the cost of the final product. This solution is much better than a conventional
stabilizer due to double conversion.
The correction of the power factor (PFC) in the no break is necessary to reduce the cost
of the electric energy, as it reduces the reactive power (VAr) and the total power (VA).
It is important to emphasize that it is not efficient to have a transmitter with power factor
correction (PFC) powered by a no-break without PFC, as all the advantage achieved
by the transmitter is lost in the UPS, resulting in no energy savings. When this type of
connection made you actually have an excellent load (resistive behavior) for the no-
break but your power grid will see the no-break input (without PFC, high consumption).
When we have a power factor correction (PFC) UPS, it perofrms well (low reactive
power, low power consumption) within the network even if it is connected to a PFC-free
transmitter, as it will correct the power factor of the entire system.
No break example with Isolating Transformer
E-Compact MP-BB3 Series
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