Description

AVR MECC UVR6

Bo điều áp AVR Mecc UVR6, được sử dụng trên đầu phát MeccAlt; Nguồn sensing: 1 pha-220V; Kích từ : F+,F-; không chuổi than.

General characteristics:

The AVR MECC UVR6 type voltage regulator is an advanced design electronic regulator that ensures excellent performance of the alternators while they are running and during starting. The regulator is equipped with a
complete protection system against operation conditions that could be dangerous for the machine. The UVR6 regulator is suitable for being used with all Mecc Alte alternators and is standard supply for power outputs above or equal to 85 KVA, both three-phase and single phase.

The components of this regulator (see fig. 8) are modern utilising solid-state integrated circuit technology. These components were chosen to guarantee maximum durability and reliability. The entire unit, also made using a hybrid circuit, is inside a box of modest dimensions that has been impregnated with resin to protect against vibrations and ingress of water.

The terminal board is equipped with indications to help connection and avoid errors. Some connection diagrams that are suitable for different configurations are given on the back of the regulator (see fig. 9).

Technical characteristics:

Supply:
The supply to the regulator can be from 170 to 270 Vac between terminals + and 2 of the terminal board, with + and B not connected, or from 80 to 160 Vac between terminals + and 2 but with + and B connected to each other. Supply can also be separate from the sensing and in this case should be insulated from it.

Sensing:
The regulator is equipped with three differential sensing inputs (terminals 1-2, 3-4, 5-6), which measure
up to three different machine voltages. In this way you can check the average voltage on one or three phases
of your choice.
The most common connections are the following:

a) Direct voltage adjustment of one of the phase windings, with the machine either star or delta connected.
b) Direct adjustment of the voltage of the three phase windings (also for 12 terminal machines), with the machine
either star or delta connected. In both cases (“a” and “b”), the passage of the machine connection from triangle to star does not need regulator connection modification.
c) Direct adjustment of the voltage to the terminals being used, with machine either star or delta connected.

Adjustments:

Voltage precision:
The voltage remains within ±1% of the pre-set value when passing from zero to full load, from cos ϕ 1 to 0.8 and with turn variations of up to -6% of the nominal value. The precision of the voltage improves if the regulator sensing inputs are connected directly to the terminals being used (see point c of the previous paragraph).

Voltage adjustment:

The voltage can be adjusted using the potentiometer marked “VOLT”. It is also possible to regulate the voltage at a distance of ± 5% by inserting a 100 kOhm potentiometer onto the relevant terminals of the terminal board that are marked
a variable resistance symbol.

Transitory reply time adjustment:

The regulator is equipped with a “STAB” stability potentiometer with which it is possible to vary the regulator reply in a way that limits the swing and obtains from the machine a minimum voltage reset time at nominal
value, after the application or release of a load. This permits optimum use of the UVR6 regulator for the whole range of Mecc Alte alternators.

Protections:

The UVR6 regulator is equipped with two protection systems, and when they intervene the following LEDs light up:
a) Delayed protection for overloads (yellow LED).
b) Low speed protection (red LED). Both protections have an intervention threshold that can be adjusted using the respective potentiometers. The protections cause an output voltage decrease that reduces the excitation current of the machine, so reducing overheating of the exciter rotor. The overload protection has a delay that let’s the machine overload briefly, for electric motor starting or other needs. The regulator also has a third LED (green) which when lit indicates that the regulator is working correctly. All these signals can be observed remotely using the S.P.D.96/A type “REMOTE PROTECTION SIGNALLER” that is available upon request (see paragraph 3).

Fuse:

The UVR6 electronic regulator is equipped with a fuse, which protects the alternator from overheating in cases of regulator malfunction. The fuse can be replaced easily, but the new one must have the same characteristics as the one being replaced (250V – 6.3A, quick acting, F type).

Usage field:

The UVR6 can be used with all voltages from 80 to 480 Vac at 50 Hz. It can also function at 60 Hz by bridging the “60 Hz” terminals of the regulator terminal board. The admissible calibration field corresponds to the one specified for Mecc Alte alternators.

Self-excitation:

The regulator is equipped with a “starter” device that utilises the residual voltage of the machine for supply and excitation adjustment. This permits safe alternator excitation, also with very low residual voltages and in very short time, avoiding voltage swings during the starting phase. In this way, the voltage rises to the stabilised nominal value, approximately at the same moment when the speed reaches nominal value, even with prime movers with very fast starting ramps.