Electro Instal Constantin offers installation, commissioning and servicing services for standby sources serving a wide range of objectives.

We also offer consultancy for finding the best technical and economical solution to cover all your requirements related to power supply from backup sources.

We present below the main power supply solutions:

Generating sets are sources that are installed at consumers for basic supply (isolated consumers, cottages, construction sites in the initial phase, etc.) or as replacement backup sources. The latter solution is applicable to consumers with category zero or category 1 receivers, which require a high level of supply reliability that cannot be provided by supply from the external system. This category includes vital receptors.

Vital receivers, which need to be provided with local back-up power (replacement power supply), fall into two categories:

  • receivers that do not allow power interruptions longer than one second;
  • receivers that can be interrupted for 1-5 minutes.

In case of unavailability of the external system (basic power supply), the first category of receivers is supplied from the internal system with uninterruptible power supplies, while the receivers of the second category are supplied from the internal system (replacement power supply) with generators.

The generators cover the power range 5-1400 kVA. A genset will only operate stably if the load is at least one third of the rated power of the generator at a power factor of 0.8.

The following factors should be taken into account when choosing the generating set and determining its apparent power:

  • the altitude of the location of the generating set
  • the air temperature in the area and its relative humidity and the total power factor of the load, if less than 0,8.

In the case of starting high-power electric motors driving heavy starting machinery (fans, centrifugal pumps, turbochargers) it is necessary to bear in mind that the shocks produced when they are started may result in voltage and frequency drops, which the electronic protection equipment in the control panel will interpret as fault information, thus disconnecting the unit.

Therefore, all electric motors whose power exceeds 10% of the generator power, as well as those driving heavy starting machinery, must be fitted with electronic starters so that the current

Generator set – basic source

The generator set is also used as a basic source of electricity for supplying cabins, homes in remote areas and even machinery on construction sites.
Stationary or mobile generators can be used to supply electricity to a dwelling, providing between 1.5 and 3 hours of operation.

Generating sets with a power of between 2.5 kVA and several tens of kVA can provide an optimum supply of electricity to the machinery on the site. The advantages of using generators to supply electricity to construction sites are as follows:

  • the opening and organisation of construction sites is not conditional on connection to the local electricity networks;
  • the operation of site installations is not subject to the specific requirements of the electricity distribution networks, as well as limiting peak load at certain times of the day and achieving a power factor as close to unity as possible;
  • absolute freedom of movement of equipment from one point to another;
  • total independence from interruptions in power supply caused by faults in the supplier’s network.

Parallel operation of generating sets with the grid ensures compensation of peak loads beyond the limits imposed by the electricity supplier and improvement of the power factor.

 UNINTERRUPTIBLE POWER SUPPLIES – UPS (Uninterruptible Power Supply)

In various situations, it is necessary to supply power from a source that does not cause interruptions or distortions of the voltage sine wave. This is the case for computing equipment, electromedical equipment in operating theatres and intensive care units, control rooms, warning and fire-fighting installations and, above all, those related to national security.

Three distinct elements are required to ensure an uninterrupted power supply:

  • an auxiliary power source, independent of the grid;
  • a converter of this energy into electricity, having the same parameters (number of phases, voltage, frequency) as the grid from which the equipment is currently supplied;
  • a system for monitoring the voltage from the external supplier’s network, switching to the non-reruptible backup source provided by the consumer.

A battery of accumulators on permanent charge is preferred as a back-up power source. These accumulators shall be of the non-gassing and maintenance-free type and shall be automatically recharged by means of a controlled rectifier. They have a lifetime of 5-6 years, after which their capacity drops below 80% of their original capacity. Some battery manufacturers no longer use sulphuric acid, but a paste (gel) that allows them to operate in any position.

The inverter, which converts the DC voltage of the accumulators into AC voltage. The starter battery of the group is kept permanently charged.