BRPI1003981A2 - 1250 / 250a transfer switch with mechanical lock - Google Patents

Abstract

1250 / 250A TRANSFER KEY WITH MECHANICAL LOCK. The present application concerns a transfer switch for the purpose of switching from an alternative source for the maintenance of trains or any equipment with mechanical interlock and electrical and mechanical interlocking so that the operator can perform safe isolated and protected maneuvers. and without the fear of performing any wrong procedure, with safety as its primary objective, both on the outside of the fully insulated 75OVcc, 250A powered plug

Description

"1250 / 250A TRANSFER KEY WITH MECHANICAL LOCK" OBJECTIVE

The present application concerns a transfer switch for the purpose of switching from an alternative source for the maintenance of trains or any equipment with mechanical interlock and electrical and mechanical interlocking so that the operator can perform safe isolated and protected maneuvers. and without the fear of performing any wrong procedure, with safety as its primary objective, both on the outside of the fully insulated 750Vdc, 250A powered plug and following IP 67/65 protection standards.

Such a procedure is always done with de-energized equipment, but with this new key, even if the operator wants to miss the procedure, he can not do so, thus resulting in safety.

INTRODUCTION

The single drive transfer switch for ancillary services without any kind of lock, as the box is open and subject to operator traffic and maintenance equipment could occur some kind of incident.

The problem to be solved was in particular to provide a safe way to maintain rail car wagons used for metropolitan transport.

This switch works with a current of 250A, under voltage of 750Vdc when under maintenance, however, with the trains was movement, it must support a current of up to 1250A.

The solution found by the depositor was the development of a product based on a mechanical locking socket in a single equipment, combining robustness and safety as described throughout this application.

Said product consists of a new transfer switch which is no longer insulated knife-type to a 1250A fully shielded handle and opening and closing on-load rotary switch to prevent accidents or incidents.

TECHNICAL STATE

The power supply to the trains comes from an energized rail, this rail feeds a switch arranged inside a box. The opening of the box is done with the train stopped, having a micro key that automatically drops the power supply to avoid any incident, but this micro is reversible, because in some moments we need to have the box open and work with feed in the wagon, this follows each company's procedures.

Inside the box is a knife-type wrench with the following positions:

1 - Knife switch handle, isolated with all active part energized without protection to make contacts. In this position the feed is through the rail

entering the switch between positions 2 and 3 and the output is in position two which is divided into two traction and auxiliary service circuits. 2 - Outgoing power position for the 750Vdc 125OA traction circuits and above the 750Vdc but 250A auxiliary services circuit.

3 - Knife switch base position to move everything off or reverse power to external source

for maintenance of the train in the workshop, ie an external power supply that will have to be of 750Vdc, but only at 250A since there is no need for traction, because the engine repairs are external to the train and it needs lighting, ventilation and other ancillary services.

It also has the function of short-circuiting the supply or contact of position four with the auxiliary circuits and of supplying the auxiliary services when the train is stopped, since the traction circuits and auxiliary services are independent in their output.

4 - Knife switch position to fully open power contacts and close with an "external power supply.

- Inlet of the 750Vdc 250A external power pacifier is made unreliably subject to incidents and can be loaded with the pacifier, ie energized and can also be removed causing arches and probable operator discomfort.

- A micro switch disconnect a command to automatically drop a contactor when the key door opens

It feeds the power contacts, but this micro-switch needs to be bypassed for train maintenance, this does not cause safety problems, but without electrical and mechanical interlocks, undesired conditions may arise for operators.

When energizing from an external source, there are a number of risks of involuntary arcing or contact. The pacifier part is very little isolated and the lack of

security is huge.

Knowing all the problems mentioned above, a definitive solution to the safety problem and power interlocks was presented according to the request described below.

BRIEF DESCRIPTION OF THE FIGURES

This request will be explained in detail with the

help of the attached figures.

Figure 1 illustrates in a perspective view.

front, the transfer switch assembly, object of the

present request;

Figure 2 shows a front perspective view.

upper, the transfer switch assembly;

Fig. 3 shows another front perspective view of the transfer switch assembly;

Figure 4 shows a front perspective view.

of the switch body of 1250A;

Figure 5 shows in rear perspective of the body.

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1250A power switch; Figure 6 shows a perspective view of the

electrical switch assembly outlet;

Figure 7 shows a perspective view of the

electrical switch assembly plug;

Figure 8 shows a perspective view of the power switch socket base assembly;

Figure 9 shows a perspective view of the socket assembly and power switch drive assembly;

Figure 10 shows a perspective view of the assembled wrench assembly;

Figure 11 shows the perspective view of the drive assembly;

Figure 12 shows the exploded perspective view of the drive assembly;

Figure 13 shows the perspective view of the tongue locking the plug to the electrical lock assembly; Figure 14 illustrates the operation of the mechanism

locking the handle, preventing it from being moved to position 2, without the plug being connected to the power switch socket; and

Figure 15 illustrates the plug attached to the power switch with the handle in position 2. In this condition, the plug is locked by the "" tongue and cannot be removed without the handle returning to position 0 (zero).

DETAILED DESCRIPTION OF THE INVENTION

According to figures 1 "to 4," the 1250 / 250A transfer switch assembly (1) comprises a metal housing (2) provided with a flip-off lid (6) containing a micro switch (5), a wrench (3) and a plug (4).

As shown in figure 10, the electric key assembly (3) comprises a drive handle (7) which has three distinct stopping positions, namely:

- position "0" (zero): off;

- position "1": normally connected in operation of the

train; and

- position "2": connected with the plug (4) coupled for the maintenance of motors. The electric switch assembly (3) further comprises a socket (8) for coupling the plug (4), the socket cover (9) and a drive assembly (10).

Figures -8 and 9 illustrate the mounting of the socket base (12) on the switch body (11) as well as the mounting of the

drive assembly (10).

Figure 11 shows the drive assembly (10) assembled and Figure 12 shows the drive assembly (10) in an exploded view, in which it is observed that this drive assembly (10) is composed of a body (13). , a coil spring

(14) and a stem (15).

Figure 13 shows the locking tab (16) which is also visible in figure 8.

The plug (4) has 5 poles according to IEC standard, with some modifications to meet the requirements of 750Vdc of nominal voltage and also with 3 poles for rated current of 25OA in direct current, we are using three parallel pins that would not be necessary, but To increase safety and decrease temperature and not go out of standard, this technology feature was preferred.

In the control part, a pilot pin and a small pole were placed so that they are always the last to make the contacts and always be the first to open the contacts, a fourth pole was also used. would be NEUTRAL in a standard component to be the command return, but we have decreased its size leaving it with a standard contact size of 63A for closing the 125Vdc command at 10A.

This means that this plug (4) is always placed on the transfer switch (1) with de-energized equipment and if there is a fault, the command is the last one to close avoiding any kind of spark type incident. consequently, if there are any faults, the withdrawal also makes it impossible to make an arcing, since the contacts will always open first and the command will be switched off and the power circuits will be opened - not on the switch but on the contactor ■ of the contactor. command, which was also developed to meet standards and safety.

There is also the fifth pole that is grounded, for various reasons we will not go into details of this pin, as it is normal and we always have to have the grounding pin, it is up to each user to use it in their circuit or make a separate ground. for any insulation failure and also give a voltage reference to the system.

This plug (4) also has a cable "strain relief" to prevent misoperation due to displacement of the plug (4), always remembering that these devices are IP-67 although we know IP-65 perfectly meets development.

All plug (4) is found to be of insulating material and there is a plug retaining ring (17). (4) on the switch (3) this to ensure excellent electrical contact between the plug (4) and the power input socket (8) to power the auxiliary circuits.

Such assembly has already greatly improved the operational and safety part for the operators, however, it was sought to make a switch that was fully shielded against direct and indirect contacts, and that also had a mechanical interlock with the external power for to avoid problems.

The auxiliary service outlet (8) and plug (4) are 750Vdc with a rated current (In) of 250A. At the closing of the transfer switch in normal operation, ie during train operation, the rated traction current (In) is 1250A, so a plug (8) was designed, with locking: 250A mechanical for services. auxiliary and with a 1250A switch for when in normal operation without external power.

A neutral position was also provided, that is, a position where everything was off, this meant that the key was made with three positions being one off or position 1, which is actually the traction on position. , ie the train running normally with an (In) of 1250Δ in its contacts. In position "1" the switch contacts are closed

powered by the key rail directly and is splitting into the traction circuits and auxiliary circuits, with an arc extinguishing chamber and this, besides being very efficient, is safe if there is a problem of opening over knowing that the purpose and all the procedures are to prevent this from happening. This switch is ready for such a situation. In addition, this camera is removable for maintenance and checking of the contact conditions. strength of the key, with this in addition to meeting the security - the key facilitates preventive maintenance

In position "2", we have the traction cable output for the sectioned power of the train.

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To describe the position "2" of the switch, there are other interlocks with the mechanical lock, that is, we can only place the switch in this position if we first put the plug (4) properly connected to the socket (8) to release the mechanical locking so that we can turn the key to position "2". Without inserting the plug (4), the key cannot be turned on, ie going from position "0" of everything off to position "2". There is a mechanical lock, only released with the placement of the plug (4), being a safety and a process that does not depend on procedures but on mechanical logic to avoid accidents and incidents. Figures 14 and 15 illustrate this locking mechanism. It can be seen from figure 7 that the plug (4) has a shoulder (18) located at its bottom. In turn, the drive assembly 10 shown in FIGS. 11 and 12, when mounted under the socket base 12, protrudes the pin 15 so that the tongue 16 is prevented from advancing. when handle (7) is actuated from position "0" (zero) to position "2". In figure 14, it is noted that by inserting the plug (4) into the socket (8) (not shown for clarity of illustration), the shoulder (18) pushes the pin (15), acting against the spring ( 14). At the end of the plug coupling (4), the shoulder (18) is in a position where the tongue (16) is released to advance, when the handle (7) is actuated from position "0" (zero) position "2", while the tongue (16) is positioned over the shoulder (18), thus preventing the plug (4) from being removed without the handle (7) being moved from the position "2" to position "0" (zero), returning the tongue (16) to the starting position. 20 ..........- ■ In this position "2", the switch (3) closes an auto-

that allows us to close the contactor that feeds the auxiliary services and only then would be able to energize the circuit very well interlocked without the need for procedures if the operator does something wrong the switch (3) does not turn on, ie safety, quality and certainty of a good connection.

After the switch (3) is in the "2" position, whether the auxiliary circuit is energized or not, the operator can no longer remove the plug (4) from the socket (8), ie there is another interlock, he would have to turn the key off to the "0" (zero) position in order to remove the plug (4) from the socket (8), this closes the connection on power up and off, all very well interlocked with connection quality and great safety for the operator and bystanders.

The micro (5) is intended to overturn the power limit circuit when the door (6) of the transfer switch housing (2) is opened. This micro (5) acts on the controller by knocking down the power circuit to avoid any kind of maneuver with load even though this switch is ready for it.

Optionally the transfer key assembly

(1) can be supplied without metal case (2).

Claims (5)

1.) 1250 / 250A TRANSFER KEY WITH MECHANICAL LOCK ", characterized in that it comprises a metal housing (2), fitted with a tilting lid (6), containing a micro-key (5), an electric key assembly ( 3) and a plug (4). 2. "TRANSFER SWITCH" according to Claim 1, characterized in that the electric switch assembly (3) comprises a drive handle (7) with three distinct stopping positions, a socket (8), the socket cover. (9) and a drive assembly (10) and locking tab (16). 3.) "TRANSFER SWITCH" according to claim 1, characterized in that the drive assembly (10) does not permit the change from position "0" (zero) to position "" 2 "by means of locking tab (16). 4.) "TRANSFER SWITCH" according to claim 1, characterized in that the locking tab (16) prevents removal of the plug (4). 5.) "TRANSFER KEY" according to Claim 1, characterized in that it can be supplied without the metal housing (2).