What is an Isolating Driver?

More information .....

I have located the technical info on this product but i still don't understand what this item does.

http://www.mtl-inst.com/images/uploads/datasheets/4000/INM_MTL4000.pdf

I'm sure that will help out you people who actually know what you're doing though.

This is a standard (could be MIL-Spec) connector - could carry data, power, etc. I don't know the classification to use for HS codes, but I will try to find out.

The Corp. I work for makes them, it's just a shell(machined,molded), contacts(machined, stamped), and molded insert, along with probably helical screws for clamping

(I hope your buying these from the right company (mine)

Thanks for the quick reply.

If I ever buy one I'll put your company at the top of the list, I only move them across borders for my clients who do the buying.

Does it do anything else other than make a simple connection? Does it alter the signal? You mentioned data. Why so complex to just make a connection. (pardon my ignorance)

If it is a simple connector it would fall under 8536.

Electrical apparatus for switching or protecting electrical circuits, or for

making connections to or in electrical circuits (for example, switches,

relays, fuses, surge suppressors, plugs, sockets, lamp-holders and

other connectors, junction boxes), for a voltage not exceeding 1,000

volts; connectors for optical fibres, optical fibre bundles or cables.

If it alters data though it might be more like 8517.

Machines for the reception, conversion and transmission or

regeneration of voice, images or other data, including switching and

routing apparatus

OK. 8536 also covers things like fuses and circuit breakers or other articles "for the protection of electrical circuits". Is that a fitting description of the device?

Hi JRaef - so by your description, should/can this be classed as a relay?

Relays also mentioned in 8536.40

looks like we are heading that way so let me show you guys the breakdowns in 8536

8536.10 fuses

8536.20 Circuit breakers

8536.30 Other apparatus for the protection of electrical circuits

8536.40 relays

8536.50 switches

8536.60 Lamp holders and sockets

8536.70 connectors for optical fibers

8536.90 other app. for switching, protecting or making connections in electrical circuits.

Apothicus,

This link should give you the exact details you asked about. It is a valve positioner.

Regards, CJM

Hmmmm, I don't think you quite get the nature of the game here CJ. I have to classify the product within the terms of the tariff and the rules of classification to satisfy the customs officers who will issue large fines if i get it wrong. So valve positioner may be what it does but not what it is.

So if someone could say with assurance that the item is a switch, a relay or a surge protector I can then proceed. Perhaps it is all of those in which case it will fall outside 8536, perhaps here....

Boards, panels, consoles, desks, cabinets and other bases, equipped

with two or more apparatus of heading 85.35 or 85.36, for electric control

or the distribution of electricity, including those incorporating

instruments or apparatus of Chapter 90, and numerical control

apparatus, other than switching apparatus of heading 85.17.

See I'm just looking for a descriptuion of what this does and how and I will fit that description into my knowledge of the tariff.

It most closely resembles:

8536.30 Other apparatus for the protection of electrical circuits

JRaef in post 4 had it spot on: "The sole purpose of the device is to isolate that original 4-20ma signal from direct contact with the process controller, so that if something goes wrong with the process field instrument that is generating it, or with the wiring or connections in the field, it does not damage the VERY expensive process controller." (Italics mine)

Apothicus,

I thought the description might give you or one of the other contributors a greater detail of the exact nature and usage of this device.

Apparently it is used to connect the controls of a valve to the control circuitry where non explosive connectivity is required. The component parts are listed.

"An MTL4046 isolating driver, 4-20ma, for HART valve positioners enables the interconnection of apparatus located in the hazardous area with unspecified apparatus located in the non-hazardous area. The MTL 4046 is designed to restrict the transfer of energy by limiting the voltage and current.

The MTL4046 apparatus comprises three isolating transformers, which provide galvanic isolation between the hazardous area and the non-hazardous area circuitry, and a detection circuit with zener diodes/transistors to provide voltage and current limitation. The above, along with other electronic components are mounted on a printed circuit board and housed in a molded plastic enclosure. Terminals are provided for the hazardous area and non-hazardous area connections."

Does a valve control circuit isolator between hazardous and non-hazardous zones match up to any of your categories? CJM

'8536.30 Other apparatus for the protection of electrical circuits' seems closest. As others have said it is a signal isolator but others have missed that its PRIMARY purpose is an intrinsic safety galvanic isolator (signal isolator) for use in flammable atmospheres (hazardous areas), specifically for use with a HART protocol valve positioner.

http://en.wikipedia.org/wiki/Intrinsic_safety

Here is the certificate for the device (I don't know if it is current). It also has more details and may be wise to include it in any declaration documentation (if any is required in Canada, etc)

http://194.203.250.243/certs_1.nsf/0f2ac981610bbc77002568be0055d6cc/bbf10f1064bb64fe8025707c00549779/$FILE/97690710.pdf/iecex.bas.05.0058.pdf

There is nothing fancy or hazardous with this type of goods, its primary purpose is electrical isolation using electronic means.

It is a "signal transmitter" for industrial purposes.

It will transmit over two or three wires a signal 4-20mA that is the electrical equivalent of a physical measurement (voltage, resistance, etc), signal that might be used even to drive a proportional valve. Reversely, it can be used to transit the electrical equivalent of a valve opening.

It is isolator, that means that it is safe to be used to transmit signal between two industrial devices that might be at different voltage potential.

The previous post by CUTiger is miles off the mark, that is referring to the backplane that the MTL4046C plugs in to.

Refer to page 23 of the document you linked to. The MTL4046C is an Intrinsically Safe (IS) isolating driver barrier that supresses potential ignition energy from leaving the safe area and being transmitted to the field device.

This module does not change the analogue signal (not data), but simply repeats it.

It's purpose is to drive a 4-20mA output to a field device, eg control valve, actuator etc.

For more specific info, refer to http://www.mtl.de/pdfs/Serie_4000/EPS4046S.pdf

By the way, it is NOT intended to protect the control system. It is certified for use in conjunction with a hazardous area field device that is located in in an area that may have explosive gases/dusts.

The problem here is, we are all thinking like Engineers. Poor Apothicus is only interested in the legal / taxation classification which, as I said, was NOT put together by Engineers...

From all of the other descriptions you posted, I still think the one I thought it might be in my first post (can't see it here in this reply pane) fits it the best.

When I have been forced (usually at gunpoint) to do this sort of classification, I read through them and find the one that triggers the lowest tax rate which has some reasonable resemblance to what the thing might do. I have never been challenged, probably because whatever clerk is looking at the paperwork has no clue either. In my mind, I always go to that image at the very end of the movie "Raiders f the Lost Ark" where some government warehouse worker is wheeling the Ark in a crate through a vast warehouse of forgotten stuff... nobody really knows or cares, as long as the paperwork gets properly filed on time.

Good luck with that

Apothicus

The thing can be called:

- an electronic signal relay; or

- an electronic signal isolator.

All the thing does is read an electronic signal at its inlet and reproduce it at the its outlet. The thing's 'isolating' capability consists of there being no connection between the inlet and the outlet; in other words, the inlet and outlet are isolated from each other.

Whatever's connected to the inlet has no connection to (is isolated from) whatever's connected to the outlet.

MZ

The device is an instrumentation circuit isolating device, intended for use on circuits where there is a risk of igniting a potentially explosive atmosphere downstream of it. The device regulates the power and voltage levels in the downstream circuit so that this cannot happen.

http://194.203.250.243/certs_1.nsf/0f2ac981610bbc77002568be0055d6cc/bbf10f1064bb64fe8025707c00549779/$FILE/97690710.pdf/iecex.bas.05.0058.pdf

This particular one is intended for use where a modulating process valve is inside the potentially explosive atmosphere and needs to be driven from the global-standard 4-20mA analog instrumentation control signal originating from outside the potentially explosive atmosphere's area. It can also pass signals between the panel and the device via the global-standard HART protocol.

It lives either inside a control panel or in a junction box outside the potentially explosive atmosphere when in use.

I have to thank you all for your input, but pwr2thepeople deserves special mention for going the extra mile and actually delving into my world and consulting the tariff.

We are now going to sift through all the new data, contact the Cdn. co., consult all the rules and regulations and take a leap on one tariff or the other. Believe it or not there is actually a classification rule that applies to items that are described under more than one tariff.

Again thanks to all who contributed.

Regards

"Isolating" + "Driver"

Isolating means any device which Isolates an "Input-Signal" from the "out-put Signal" Galvanically ie Electrically-Direct connections or through capacitors. It may be an Isolating Transformer or an Electronic sub-assembly isolating Optically.

Su

"Driver" means which supplies a driving-Signal [Electrical] to run an Electrical device to indicate; provide power or else

In the question it is a sub-assembly on a PCB [Printed Circuit Board] having some components on a printed-circuit-board; with some connectors 2 or 3 for

1.) for power-supply of the board itself

2.) for input signals &

3.) for Out-put signal.

Because the assembly is for 4-20 mA system which is normally used in Industrial controls for measurements in remote area

such as temperature, flow of any thing like fluid, powder.

OR

for power-control like Electrical power, Voltage, current or Frquency in an Power Inverters

[Inverter is also a part of UPS or stand-alone Assy]

OR

Speed, torque, etc in motors or Drives

All Signals are in Linear not Digital domain.

It is niether a Relay, connector nor a Mechanical fittings but an Electronic-Assembly

[Not a big one but a small part of the machine or system ]

I hope it may add to the existing information.