1 route de Semur
BP 150
21500 MONTBARD
Tél. : 00 33 (0)3 80 89 58 58
Fax : 00 33 (0)3 80 92 24 33
E.mail : info@mdresistor.com

Map to Montbard	access to MDR	Map of Montbard

By Highway A6 :
Direction Paris/Lyon A6 : take exit Bierre les Semur

By train :
TGV directs Paris / Montbard :

Schedules (except weekends) Paris Gare de Lyon / Montbard :

Schedules TGV Paris Aéroport Charles de Gaulle / Montbard :

Some Hotels from Montbard and Semur En Auxois (18km of Montbard) :

ELECTRONIC DIRECTORY

STANDARD :	TEL. : 00 33 (0)3 80 89 58 58 FAX : 00 33 (0)3 80 92 24 33 E.mail : info@mdresistor.com
COMMERCIAL DEPARTMENT :	TEL. : 00 33 (0)3 80 89 58 75
CUSTOMER DEPARTMENT :	TEL. : 00 33 (0)3 80 89 58 74

To find out the email of your contact at METAL DEPLOYE RESISTOR :

bernard.bernet@mdresistor.com
bernard.fichot@mdresistor.com
delphine.miraux@mdresistor.com
emmanuel.martin@mdresistor.com
eric.demarquet@mdresistor.com
fabien.meteau@mdresistor.com
francois.lavogiez@mdresistor.com
jean-claude.greuez@mdresistor.com
jean-louis.ragot@mdresistor.com
jean-pierre.contini@mdresistor.com
jerome.adam@mdresistor.com
karine.picard@mdresistor.com
luc.brasseur@mdresistor.com
marie-helene.dacustodia@mdresistor.com
michael.chalumeau@mdresistor.com
nathalie.gerard@mdresistor.com
patrick.beurlangey@mdresistor.com
richard.mamecier@mdresistor.com
sabine.lambert@mdresistor.com
sebastien.deligny@mdresistor.com
sebastien.lepage@mdresistor.com
yann.fouquet@mdresistor.com

Our various applications :

Energy :
- earthing,
- filtering,
- integration of related components to the resistance of power (disconnecting switches, switches, crossings, TC...)

engine control :
- for engine D.C. current ,
- stator,
- resistances of excitation, discharges, ...
- braking (lifting, translation, direction),
- electrical equipment boxes.

Vectrohm :
- démarreurs électrolytiques,
- consumable,
- parts spare.

Charge :
- bancs of load natural convection,
- charging benches forced ventilation (tunnel of charge)
- bancs of discharge, battery and load D.C.current,
- specific load of test,
- control, regulation, electrical equipment box.

Railway resistance of traction (rheostats of braking and resistances auxiliary) :
- first goes up,
- restoration.

Industrial heating :
- industrial furnaces,
- warm air heaters gas-fired.

Safety for test and regulation...	Get an estimate
In the load banks for generating sets, the resistors are used when the generator is running at low power to prevent the diesel engines from gumming up. The use of industrial resistors as load banks is also a standard practice to maintain batteries in electrical laboratories and industrial testing facilities. We can propose inductive load banks able to vary the power from 0.8 to 1.	Simulation of the load of radio transmitters. Forced ventilation resistors 500 kW BBC (Switzerland)

STANDARD PRODUCTS

Natural cooling 15 kW under 400V	NATURAL SERIE : . Natural air cooling, . Power from 5 to 120 kW under 400 V 3 phases, . Connection in low part (cold area), . Protection level IP13 (outdoor normal use), . Options : terminals bar (DIN), IP23, castor wheels.
100 kW and 400 kW under 400 V 3 phases - Forced air cooling	AIR COOLING SERIE 400, 700 AND 800 : . Horizontal forced air cooling. . Power from 50 to 1200 kW under 400 V 3 phases . Helical fan with 400 V  motor IP54. . Air flow control by switch. . Options : terminals bar on side, castor wheels, double insulation.

SPECIFIC PRODUCTS

BANC DE CHARGE 21 MW

Our technical know-how and means (CAD, finite elements calculation, internal laboratory for heating and vibration) enable us to design customized equipments : . load resistor type "Tunnel" (beside) in air flow duct, . High voltage and high frequency, . Vertical forced cooling, . Reactive additional load, . Control module for switching, automatic regulation.

For more details, please contact us or ask us to get an estimate.

STANDARD PRODUCTS

SPECIFIC PRODUCTS

Gridex U:
For standard applications, no matter whether the period of operation is short or long, Gridex U resistors combine the thermal capacity of Gridex G resistors and the technical characteristics of Gridex N and F resistors, although their design is less complicated. Gridex U resistors consist of solid strips, extra-extended diamond meshes and lateral stiffeners.

Gridex N & F:
When the current transit through the resistor provokes heat dissipation into the surrounding environment (non-adiabatic heating), the resistor must be designed to optimize heat exchanges. This is the case of Gridex N and F resistors. Gridex N resistors are intended for natural ventilation, Gridex F resistors for forced ventilation.

Gridex G:
When a resistor does not produce any significant heat exchange with the surrounding environment (adiabatic heating) when heated, it should have as great a mass as possible. This is the case of Gridex G resistors, which consist of steel sheetmetal elements cut into rectangles and mounted in staggered configuration.

Gridex T:
The Gridex T resistors are made of woven resistive elements. The chain warp thread wire is not conductive, the weft thread is resistive . This technology allows high resistance values (reaching hundreds of ohms) and can be adapted to high voltage application (continuous or transient)

LIQUID RHEOSTATS

Vectrostar R :
The Vectrohm electrolytic staters are rheostats that always work in the liquid phase. This technology provides a continuous and progressive variation of the Resistance value.Therefore, motors are started very softly using these resistors

Braking - Atlantic TGV (Picture by Alstom)

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Today several electrical equipments generate current distortions in networks. Those distortions, named harmonics, can be modelized as a collection of sinus current at different frequencies and amplitudes added to the basic network current. They cause many different sorts of problems, such as : - Increased losses, - Malfunctioning of control system, - High currents in phase and neutral.

Filtering resistor 130 kW pt - 347 ohms

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Most power distribution networks have their neutral earthed to support important currents whenever a fault happens. In order to avoid the damages and disturbances such faults can provoke, a resistor is fitted between the neutral and the earth to limit this current and to give electrical protection devices enough time to react.

Click here for Technical Data

To check the caracteristics necessary for the calculation of your resistor, do not hesitate to contact us or ask an estimate.

ELECTROLYTIC STARTER

PRINCIPLE

Thanks to the VECTROSTAR R principle, the user obtains the maximum torque at very low speed (starting of locked and loaded machines can be accomplished). Start-up current for slip-ring motors from 0,5 to 1,5 rated current in.

PERFORMANCES

• Drastic decrease in start-up overcurrent.
• Adjustement of maximum torque with minimum current.
• Suppression of mechanical shocks through a constant acceleration torque and progressive speed increase.
• Enables a number of start-ups in a row without any possible damage to the resistivity.
• Suitable for a wide range of motors allowing motor and machines changes

ADVANTAGES - SMOOTHESS

The continuous and controlled decrease in rotor resistance provides start-ups without mechanical snatches.

ADAPTABILITY

The dosage of the electrolyte allows a perfect adaptation of VECTROSTAR R to the operating environment of the motor (resistant torque, inertia, load, etc...). The duration of the start-up depends on the dosage of the electrolyte, as well as on the adjustment of the flow valve which controls the electrolyte flow entering the start-up tank.

CONSISTENCY

The electrolyte reserve tank is large enough to allow an efficient circulation into the start-up upper tank. Subsequent start-ups can be made without changing their characteristics.

SECURITY

The VECTROSTAR R envelope provides an electrical insulation, except for Vectrostar from R 1500 up to R 4000 which have to be earth connected).
A thermostat monitors the electrolyte temperature inside the start-up tanks.

ROBUSTNESS

IP 569 protection, corrosion resistant equipment, limited maintenance is required. The starters from Vectrostar R 1500 to R 4000 are built in stainless stell. 5AISI 304L as a standard).

RELIABILITY AND MAINTENANCE

• Low operating temperature minimizes electrolytic fluid maintenance.
• Anti-corrosive electrodes eliminate oxidation and breakage.
• Unit can be installed in any location. Harsh environments are not a problem.
• Standard unit controls permit full automation of start-ups.

ECONOMICAL

Installation flexibility and low maintenance make the VECTROSTAR very economical.

SELECTION CHART

VECTROSTAR R : ELECTRICAL DIAGRAM

This electrical diagram is not exhaustive. We can propose different options and supply the specific electrical diagram you could require.

The use of expanded metal resistances of weak thermal inertia makes it possible to heat with a high degree of accuracy and without polluting it an intended gas, for example, to dehydrate medicinal or chemical foodstuffs.

It is for these reasons even as new industries turn to the resistance heating.

Insulated neutral (fig.1) - This technique which induces important risks in the event of earthing of a phase is used only on networks of small size and weak tension .

Earthing direct of the neutral (fig.2) - The neutral of the system is directly connected to the ground. In such a case, the current of short-circuit can reach 20 to 30 times the value of the rated current.

Earthing of the neutral with limitation of the fault current (fig.3) - This technique consists in inserting an impedance between the neutral and the ground. There are 3 types of impedances :

1. Résistance
2. Réactance
3. Wind of extinction of arc (winds of Petersen)

Of these three methods, only that using a resistance allows a detection simple and fast defect, while offering a potential of reference of which stability is suitable, the control of the current of short-circuit artificially created and a maximum safety for the environnement.

CALCULATION AND DIMENSIONING

The calculation of a resistance of earthing is done starting from the three criteria according to :

• t (en s.) duration of the defect
• U (en V) tension made up of the network
• I (en A) intensity of the current crossing resistance during the defect

One deduces the value from it from resistance by the formula:

The mass of resistance is then obtained by calculating its adiabatic heating lasting the defect thanks to the simplified equation :

All our resistances of earthing are conceived in respect of the standards lEEE32-1972 and lEC289 which defines an acceptable maximum temperature of resistance according to the duration of the defect. This temperature for resistant stainless elements is of 760°C for a defect of duration lower or equal to 600 seconds and of 385°C for a defect of higher duration.

PRESENTATION

This technology enables to propose Power Resistors with high Resistance values (up to several hundred ohms).
Moreover, these resistors are particularly well adapted to applications requiring high voltages (continuous and transitory).

THE RESISTIVE WIRE

It is the woof of the mat. The wire diameter can vary from 0.3 to 2mm.Various alloys are available as standards (from Konstantan which has a zero temperature coefficient, to stainless; steel type alloy or iron-chrome-aluminum). The P distance (Fig 1) varies accordingly to the wires nature and diameter, and is usually between 1 and 5 mm.

THE CHAIN WIRE

It has to maintain the resistive wire as well as to keep an optimum coefficient of thermal exchange. A E class fiberglass is proposed as a standard. It presents the following advantages:

• high temperature withstanding :
  • above 450'C for short time ratings
• low coefficient of linear thermal dilatation. The mats have a low length variation according to temperature which makes the fixation simple.
• excellent hot mechanical tensile stress resistance,
• strong resistance to pollution (except fluorine pollution).

A wide range of materials (cotton, kevlar, silica fiber) can be proposed for specific applications.

DIMENSION AND DESIGN

The weaving process provides a large flexibility in the choice of the L and 1 dimensions.
However, in order to rationalize our products, we propose 2 standard widths :160 mm and 250 mm.
The plain strips at the ends are used for mechanical fixation and can also take part to the electrical insulation.
We currently use two different arrangements (Fig.2) : the mats can be used as independent resistors, either fixed between 2 supports ensuring the insulation, or in a " U " form , or rolled, to give them a sufficient inertia, in order to be self standing. In most cases, they are used in banks and connected in series or in parallel, or in a combination of both.

APPLICATIONS

• harmonics filter
• Resistor
• low discharge of high voltage capacitors
• infrared heating
• they are also dedicated to applications where space limitations necessitate a specific and sometimes complex mechanical design. This occurs in small heating units.