Three-phase supply is cost-effective option

The PV400 three phase power supply combines an attractively designed housing with a cost effective interior, with no unnecessary circuitry for stabilising the output.

The PV400 three phase power supply combines an attractively designed housing with a cost effective interior, with no unnecessary circuitry for stabilising the output.

A further feature is the individual adjustable overload current characteristic, and the possibility to monitor and analyse the quality of the line input.

The bus interface port is also intelligent, which allows the user to implement futuristic monitoring functions.

Mounting is easy: the installer simply hangs the power supply on the DIN rail, and then locks the cam with the turn of a screwdriver.

Alone the appearance of this power supply gives the impression that it is different to its competitors, this is first due to the impressive design of the housing with an orange coloured front and offset by a blue frame.

The intensive work achieved by the design engineers of this new innovative power supply starts with the housing being designed with the aim to make it easy to install in wiring cabinets.

With this accomplished design of the power supply PV400 from Block has set new boundaries with the development engineers always having the end product in mind, from the initial concept to the final product.

The aim was to design a power supply that would satisfy all the requirements for the intended application, which means a very high standard of reliability for all of the individual components.

The flexibility to achieve and deliver all of the tasks that will be required of it in the numerous applications was also a large portion of the intensive development with the thought that the unit must also be very cost effective.

What a power supply must offer when supplying a computer programmable system (CPS) is laid down in the requirements of EN61131-2.

This safety standard lists the limitations of the line and output voltages including the tolerances which were a very important factor during development.

The result of this intense development project is a primary switched three phase power supply delivering an output power rating from 240 to 960W with optimal cost effectiveness.

Block design engineers concentrated their efforts on these special specification parameters so that the PV400 is capable with this concept of offering an alternative to the present overpriced supplies with extravagant and expensive voltage stabilisation circuits.

According to most manufacturers' specifications and internationally accepted standards, computer programmable systems require a stable 24V DC with a tolerance of only -15% to +20%.

Any increase in these values does no actual harm to the CPS but is unnecessary for approximately 98% of all normal applications, thus causing a very steep price increase to the total cost.

The PV 400 is physically smaller and lighter than its predecessors, but with the use of the integrated resonance transformer achieves an efficiency of 98%.

Trust is often said to be a good character feature although controlling is still better.

The futuristic heart of the PV400 is the control circuit with all the important functions from the line voltage that can be monitored and controlled along with all internal parameters.

The three LEDs on the front panel indicate the operational condition of the supply.

Red indicates a fault condition, yellow a warning and green shows that normal operational conditions exist.

An interface also enables the individual parameter adjustment via a computer or CPS with all relevant performance details available for monitoring or controlling.

All these parameters are also shown on the integrated LCD on the front cover continually indicating to the operator the information as to the operational status of the power supply.

The standard factory setting for the display indicates the output voltage and current with the touch of a button it will show the hours of operation along with the assistance of this counter an alarm setting can be programmed to indicate when the power supply requires servicing, eg a filter needs to be renewed.

The real power boost feature will deliver an additional 100% power for 4s or 50% for 8s for the duration off this facility a warning signal will be given after the time has elapsed the PV400 can be operated in normal conditions.

If the time limit is exceeded the PV400 will automatically change into constant current mode, hiccup mode or a time limited constant current mode followed by the hiccup mode.

All relevant parameters from the running operation can be saved in an onboard memory and using the friendly menu all these parameters can be called on.

A novelty in this power supply technology is the PV400L from the Power Vision series with an integrated line input monitor.

Apart from the output status it also monitors the line input supply allowing all operational parameters and fault conditions on the input as well as the output circuit to be monitored and saved for future analysis.

Monitoring the line supply makes the analysis of a fault condition for service technicians and engineers a lot easier if they have to consider the quality of the supply voltage in there fault finding.

With a large rang of machines short term voltage drops are often enough to bring them out of tact and can be responsible for numerous fault conditions and uncontrolled switching.

This intensive fault analysis can cost the service engineer a lot of time and the customer a lot of money.

The features consist of constant monitoring of the line voltage, the frequency, a possible phase drop out, or the rotary field frequency.

The four freely programmable interface ports deliver every 0.5s the parameters of the line voltage or alternatively provide all the information to the bus interface giving constant control of all input line conditions as well as the 24V DC output to a remote service station.

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