Surge protective device modules and DIN rail device systems including same

1. A surge protective device (SPD) module comprising:

a module housing;

first and second module electrical terminals mounted on the module housing;

a gas discharge tube (GDT) mounted in the module housing, the GDT including a first GDT terminal electrically connected to the first module electrical terminal and a second GDT terminal electrically connected to the second module electrical terminal; and

a fail-safe mechanism mounted in the module housing, the fail-safe mechanism including:

a shorting bar positioned in a ready position and repositionable to a shorting position, wherein the shorting bar is electrically conductive;

a biasing member applying a biasing load to the shorting bar to direct the shorting bar from the ready position to the shorting position; and

a meltable member;

wherein:

the meltable member maintains the shorting bar in the ready position and melts in response to a prescribed temperature to permit the shorting bar to transition from the ready position to the shorting position under the biasing load of the biasing member; and

in the shorting position, the shorting bar forms an electrical short circuit between the first and second GDT terminals to bypass the GDT; and

wherein the SPD module includes:

a first carrier contact member including a first shorting portion electrically connected to the first GDT terminal; and

a second carrier contact member including a second shorting portion electrically connected to the second GDT terminal;

wherein:

in the ready position, the meltable member holds the shorting bar spaced apart from and electrically isolated from the first and second shorting portions; and

when the meltable member melts, the biasing member forcibly displaces the shorting bar into contact with each of the first and second shorting portions to form the electrical short circuit between the first and second GDT terminals to bypass the GDT.

2. The SPD module of claim 1 wherein:

the first carrier contact member includes a first GDT mount hole;

the second carrier contact member includes a second GDT mount hole;

the first GDT terminal is seated in the first GDT mount hole and secured therein by solder in the first GDT mount hole; and

the second GDT terminal is seated in the second GDT mount hole and secured therein by solder in the second GDT mount hole.

3. The SPD module of claim 1 wherein the meltable member is formed of metal.

4. The SPD module of claim 1 wherein the meltable member has a melting point in a range of from about 9° C. to 240° C.

5. The SPD module of claim 1 including an alarm mechanism responsive to melting of the meltable member to provide an alert that the SPD module has failed.

6. The SPD module of claim 5 wherein the alarm mechanism includes a local alarm mechanism including:

a window defined in the module housing;

an indicator member movable between first and second positions relative to the window;

an indicator biasing member applying a biasing load to the indicator member to direct the indicator member from the first position to the second position; and

a trigger member;

wherein:

the trigger member retains the indicator member in the first position; and

when the meltable member melts, the trigger member releases the indicator member to move from the first position to the second position under the biasing load of the indicator biasing member.

7. The SPD module of claim 5 wherein the alarm mechanism includes a remote alarm mechanism including:

a port defined in the module housing to receive a remote control pin; and

an indicator member having an indicator hole defined therein;

wherein:

the indicator member is movable between a first position, wherein the indicator member covers the port, and a second position, wherein the indicator opening is aligned with the port and permits the remote control pin to extend through the indicator opening; and

when the meltable member melts, the indicator member is moved from the first position to the second position under the biasing load of the biasing member.

8. The SPD module of claim 1 wherein the first and second module terminals are bullet connectors.

9. The SPD module of claim 8 wherein:

the first carrier contact member electrically connects the first GDT terminal to the first module terminal; and

the second carrier contact member electrically connects the second GDT terminal to the second module terminal;

the first module terminal is orbital riveted to the first carrier contact member; and

the second module terminal is orbital riveted to the second carrier contact member.

10. A surge protective device (SPD) module comprising:

a module housing;

first and second module electrical terminals mounted on the module housing;

a gas discharge tube (GDT) mounted in the module housing, the GDT including a first GDT terminal electrically connected to the first module electrical terminal and a second GDT terminal electrically connected to the second module electrical terminal; and

a fail-safe mechanism mounted in the module housing, the fail-safe mechanism including:

a shorting bar positioned in a ready position and repositionable to a shorting position, wherein the shorting bar is electrically conductive;

a biasing member applying a biasing load to the shorting bar to direct the shorting bar from the ready position to the shorting position; and

a meltable member;

wherein:

the meltable member maintains the shorting bar in the ready position and melts in response to a prescribed temperature to permit the shorting bar to transition from the ready position to the shorting position under the biasing load of the biasing member; and

in the shorting position, the shorting bar forms an electrical short circuit between the first and second GDT terminals to bypass the GDT;

wherein the SPD module includes an alarm mechanism responsive to melting of the meltable member to provide an alert that the SPD module has failed; and

wherein the alarm mechanism includes a local alarm mechanism including:

a window defined in the module housing;

an indicator member movable between first and second positions relative to the window;

an indicator biasing member applying a biasing load to the indicator member to direct the indicator member from the first position to the second position; and

a trigger member;

wherein:

the trigger member retains the indicator member in the first position; and

when the meltable member melts, the trigger member releases the indicator member to move from the first position to the second position under the biasing load of the indicator biasing member.

11. The SPD module of claim 10 wherein:

the SPD module includes a second alarm mechanism responsive to melting of the meltable member to provide a second alert that the SPD module has failed; and

wherein the second alarm mechanism includes a remote alarm mechanism including:

a port defined in the module housing to receive a remote control pin; and

a second indicator member having an indicator hole defined therein;

wherein:

the second indicator member is movable between a first position, wherein the second indicator member covers the port, and a second position, wherein the indicator opening is aligned with the port and permits the remote control pin to extend through the indicator opening; and

when the meltable member melts, the second indicator member is moved from the first position to the second position under the biasing load of the biasing member.

12. The SPD module of claim 10 wherein the meltable member is formed of metal.

13. The SPD module of claim 10 wherein the meltable member has a melting point in a range of from about 91° C. to 240° C.

14. The SPD module of claim 10 wherein the first and second module terminals are bullet connectors.

15. The SPD module of claim 14 including:

a first carrier contact member electrically connecting the first GDT terminal to the first module terminal; and

a second carrier contact member electrically connecting the second GDT terminal to the second module terminal;

wherein the first module terminal is orbital riveted to the first carrier contact member; and

wherein the second module terminal is orbital riveted to the second carrier contact member.

16. A surge protective device (SPD) module comprising:

a module housing;

first and second module electrical terminals mounted on the module housing;

a gas discharge tube (GDT) mounted in the module housing, the GDT including a first GDT terminal electrically connected to the first module electrical terminal and a second GDT terminal electrically connected to the second module electrical terminal; and

a fail-safe mechanism mounted in the module housing, the fail-safe mechanism including:

a shorting bar positioned in a ready position and repositionable to a shorting position, wherein the shorting bar is electrically conductive;

a biasing member applying a biasing load to the shorting bar to direct the shorting bar from the ready position to the shorting position; and

a meltable member;

wherein:

the meltable member maintains the shorting bar in the ready position and melts in response to a prescribed temperature to permit the shorting bar to transition from the ready position to the shorting position under the biasing load of the biasing member; and

in the shorting position, the shorting bar forms an electrical short circuit between the first and second GDT terminals to bypass the GDT;

wherein the SPD module includes an alarm mechanism responsive to melting of the meltable member to provide an alert that the SPD module has failed; and

wherein the alarm mechanism includes a remote alarm mechanism including:

a port defined in the module housing to receive a remote control pin; and

an indicator member having an indicator hole defined therein;

wherein:

the indicator member is movable between a first position, wherein the indicator member covers the port, and a second position, wherein the indicator opening is aligned with the port and permits the remote control pin to extend through the indicator opening; and

when the meltable member melts, the indicator member is moved from the first position to the second position under the biasing load of the biasing member.

17. The SPD module of claim 16 wherein the meltable member is formed of metal.

18. The SPD module of claim 16 wherein the meltable member has a melting point in a range of from about 90° C. to 240° C.

19. The SPD module of claim 16 wherein the first and second module terminals are bullet connectors.

20. The SPD module of claim 19 including:

a first carrier contact member electrically connecting the first GDT terminal to the first module terminal; and

a second carrier contact member electrically connecting the second GDT terminal to the second module terminal;

wherein the first module terminal is orbital riveted to the first carrier contact member; and

wherein the second module terminal is orbital riveted to the second carrier contact member.

21. The SPD module of claim 16 wherein the indicator member includes a flexible strip.