Stability; Insulation - Hitachi E-Compact Medium Power Series Operation Manual

It is important to establish that all the devices involved in the transmission system are that
the same potential, so that there is no DDP, favoring the equilibrium of the flow of the
atmospheric load.
It is important to state that if there is a need for chemical alteration of the soil, in order to
provide the lowest impedance, it establishes a temporary condition for not being part of the
natural chemistry of the place, thus being naturally absorbed. In this condition, preventive
soil analyzes should be conducted as preventive maintenance procedure.

2.3. Stability.

The voltages in each TV Transmitter phase must be stabilized. Use voltage stabilizers or
stabilized uninterruptible power systems (UPSs) is necessary since these devices are
capable of protecting the TV transmitter from power surges. The voltage stabilizer or UPS
design must be of exclusive use to the Hitachi Kokusai Linear TV transmitter, and shall be
sized to operate at least 30% above the kVA consumption specified by the TV transmitter.
For example, for the TV transmitter with maximum consumption of 38kVA, a voltage
stabilizer or 50kVA UPS should be used.
Input voltage variations above 15% of the rated values specified for the Hitachi Kokusai
Linear TV transmitter may cause damage to the equipment and in this case will not be
covered by the factory warranty. In addition, it is important to check the potential difference
between the ground and neutral terminals (if any) that will be connected to the Hitachi
Kokusai Linear TV transmitter. This potential difference should be at most 3V.

2.4. Insulation.

It is important to have isolation between energy stations of the shelter and the TV
transmitter, which is achieved with the usage of isolator transformers. Thus guarantee that
no AC Mains' transient coming from the shelter will be passed on to the TV transmitter or
vice-versa. Besides, Hitachi Kokusai Linear' TV transmitter features switching power
supplies that require purely sinusoidal power input, and voltage regulators or no-breaks
without isolator transformers have no assurance of a purely sinusoidal outputs. The isolator
transformer must also be exclusive to the TV transmitter and its dimensioning must use the
same standards employed in the dimensioning of the voltage regulator or no-break, ie, at
least 30% higher than the specified consumption TV transmitter's (KVA).
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).
E-Compact Medium Power
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