DCS Explorer Fuse Replaced

MTH RD posted:

When I saw this post, I assumed the issue was the type of AC waveform used as input to the Explorer.  True 60Hz AC is a sinusoidal waveform or, sine wave.  That’s the output from a simple iron and copper transformer.  It reduces the 120VAC sine wave from your wall outlet down to model train levels.  In the case of the Z1000 brick, around 18VAC.  In order to vary the AC voltage on the track the Z-Controller creates a phase control AC waveform commonly referred to as “shark fin.”  Most simple hobby controllers do it this way because it’s inexpensive and perfect for controlling older conventional trains.  Even some more expensive supplies use this approach these days but, we won’t pick on anyone here.  In contrast, the Z4K produces a smooth 60Hz AC waveform.

 The Explorer was designed to use fixed AC or DC voltage input.  Typically, and in all cases of our products, this is an AC sine wave or clean filtered DC.  The over current protection in the Explorer, in part, counts AC cycles in order to know how long there has been an over current condition.  I suspect the blown fuses are coming from shark fin inputs the Explorer doesn’t quite understand.  That said, I tried to blow a fuse using a Z1000 brick and two different Z-Controllers and couldn’t do it.  The Explorer over current protection detects the shorts caused by derailments (or a screwdriver) and kills power to the track as it should without blowing the fuse.

 Sorry for the labored explanation but, I still think this is what is going on here.  I’m just surprised I can duplicate it but, admittedly, I didn’t spend a lot of time trying and derailment shorts are dynamic.  Partial shorts (wheels skidding across the center and outer rails, etc.) are much more difficult to duplicate than dead shorts.

 So, my advice to avoid blowing fuses is, don’t do that!  And, by that I mean use a shark fin AC input and derail.  Ha, ha.  The fuse is there for exactly this kind of corner case where folks get creative with how the products are used.  If you really want to vary track voltage through the Explorer use clean AC as the inpout or, get a box of fuses and have a ball. ;-)

So I'm not quite sure what you are telling us: is the only power source safe to use without blowing fuses the one supplied? Because that won't be sufficient to run two to three trains, will it? 

I don't think using a z1000 MTH transformer is being creative, but perhaps you meant that for the other user who was using his transformer.

At any rate, I changed the fuse and haven't had a problem.

ryoung3 posted:

MTH RD - I recently RMA'd my DCS Explorer you may want to investigate ...

I had a derailment and got the "click" which I thought was my Z1000 brick (DCS Explorer was purchased ala carte, no power supply) turned out to be the fuse in the Explorer. Replaced the fuse, but when adding power back - it went straight to the track and set off bells and whistles with the loco on the track. Tried to reset - no luck, would just run power straight to the track. MTH Support stated they had not seen that before - this was a first, congratulations! They mentioned the Sales guys had seen fuses pop with a Z1000 brick - the RTR sets came with lower amp power supply and that may be the key to what you noted above.

Hope that unit finds its way to your lab and looking forward to my replacement

I will check in on this.  It will likely come back to our R&D office in MI.  There was a firmware change in the 11th hour of production to improve the protection circuit.  It's possible some units got out there without the enhancement.  With current firmware, it's really tough to blow a fuse.  Doing so still shouldn't take out the Explorer but, we can get some monster inductive spikes in model railroading.  As I've mentioned before, the Z-1000 can put out ~60A for a brief amount of time.

pdxtrains posted:

MTH RD posted:

When I saw this post, I assumed the issue was the type of AC waveform used as input to the Explorer.  True 60Hz AC is a sinusoidal waveform or, sine wave.  That’s the output from a simple iron and copper transformer.  It reduces the 120VAC sine wave from your wall outlet down to model train levels.  In the case of the Z1000 brick, around 18VAC.  In order to vary the AC voltage on the track the Z-Controller creates a phase control AC waveform commonly referred to as “shark fin.”  Most simple hobby controllers do it this way because it’s inexpensive and perfect for controlling older conventional trains.  Even some more expensive supplies use this approach these days but, we won’t pick on anyone here.  In contrast, the Z4K produces a smooth 60Hz AC waveform.

 The Explorer was designed to use fixed AC or DC voltage input.  Typically, and in all cases of our products, this is an AC sine wave or clean filtered DC.  The over current protection in the Explorer, in part, counts AC cycles in order to know how long there has been an over current condition.  I suspect the blown fuses are coming from shark fin inputs the Explorer doesn’t quite understand.  That said, I tried to blow a fuse using a Z1000 brick and two different Z-Controllers and couldn’t do it.  The Explorer over current protection detects the shorts caused by derailments (or a screwdriver) and kills power to the track as it should without blowing the fuse.

 Sorry for the labored explanation but, I still think this is what is going on here.  I’m just surprised I can duplicate it but, admittedly, I didn’t spend a lot of time trying and derailment shorts are dynamic.  Partial shorts (wheels skidding across the center and outer rails, etc.) are much more difficult to duplicate than dead shorts.

 So, my advice to avoid blowing fuses is, don’t do that!  And, by that I mean use a shark fin AC input and derail.  Ha, ha.  The fuse is there for exactly this kind of corner case where folks get creative with how the products are used.  If you really want to vary track voltage through the Explorer use clean AC as the inpout or, get a box of fuses and have a ball. ;-)

So I'm not quite sure what you are telling us: is the only power source safe to use without blowing fuses the one supplied? Because that won't be sufficient to run two to three trains, will it? 

I don't think using a z1000 MTH transformer is being creative, but perhaps you meant that for the other user who was using his transformer.

At any rate, I changed the fuse and haven't had a problem.

No, I'm not saying that at all.  Any fixed 8-24 VAC or 12-20 VDC supply rated at 6A or less should be fine.  We cannot support variable supplies.  The product is not intended for this use case.  

As I mentioned, I tried to blow a fuse using a Z-1000 with a Z-Controller (variable AC) and couldn't do it.  I'm sure that even with the Z-1000 only and no controller, there can be dynamics involved that might occasionally blow a fuse.  That is why it is there.  

The purpose of the fuse is to protect the Explorer itself from damage in the event of an unusual circumstance or power input outside of the design.

JFC454 posted:

Barry Broskowitz posted:

the supply voltage to the Explorer from the Z1000/Zcontroller is 17 volts.

That may be the source of your problem. The DCS Explorer is not intended to be used with a Z-Controller connected. You should connect the Z1000 directly to the DCS Explorer without the Z-Controlle;r.

The reason I had the Z controller connected was I was trying to see if I could run both MTH and Lionel engines on the same track using the Explorer.  Obviously the Lionel engines need their respective remotes.  Lionel engines should have 18 V or less to avoid damage.  The Fastrack switches I am using are probably the same way.   The direct output of the Z1000 is higher than that and in my experience track  voltage when using them is over 18 V.   By using the Z controller I could keep track voltage safe for Lionel but still get DCS to work as well.  My experimentation has convinced me that to be able to automatically shut off track power in case of a short without blowing the fuse the Explorer can't be used with input voltages less than voltage of the MTH bricks they were apparently designed for.  Not a condemnation of the Explorer, just means I can't run Lionel engines at the same time. 

Just to clarify, it's not at all voltage level related.  I think the issue is actually the Z-Controller itself.  The lower the voltage, the less the AC waveform looks like AC.  The Explorer is not designed to work with these types of variable AC supplies.

MTH RD posted:

ryoung3 posted:

MTH RD - I recently RMA'd my DCS Explorer you may want to investigate ...

I had a derailment and got the "click" which I thought was my Z1000 brick (DCS Explorer was purchased ala carte, no power supply) turned out to be the fuse in the Explorer. Replaced the fuse, but when adding power back - it went straight to the track and set off bells and whistles with the loco on the track. Tried to reset - no luck, would just run power straight to the track. MTH Support stated they had not seen that before - this was a first, congratulations! They mentioned the Sales guys had seen fuses pop with a Z1000 brick - the RTR sets came with lower amp power supply and that may be the key to what you noted above.

Hope that unit finds its way to your lab and looking forward to my replacement

I will check in on this.  It will likely come back to our R&D office in MI.  There was a firmware change in the 11th hour of production to improve the protection circuit.  It's possible some units got out there without the enhancement.  With current firmware, it's really tough to blow a fuse.  Doing so still shouldn't take out the Explorer but, we can get some monster inductive spikes in model railroading.  As I've mentioned before, the Z-1000 can put out ~60A for a brief amount of time.

I did some checking and it turns out all Explorers were shipped with the correct firmware.  I suspect the blown fuses are as we've discussed.  Result from variable supplies and in some cases, directly from the Z-1000 but, just some dynamic.  Again, I'll be interested in what broke on your Explorer when using the Z-1000 brick.  Oh, the sales guy (Rich) had his show display wired incorrectly.  The track with the Explorer was connected to other tracks with different power supplies, etc.  Definitely a no-no.

Thanks for the update MTH ...

I have a very simple isolated Fastrak loop layout with a bypass and powered by the Z1000 brick (conventional ZController). Replacing the ZController with the DCS Explorer only, the forward truck on one of the passenger cars followed the desired direction of the switch, the trailing truck decided to go the other way ... short, fuse blown. The Fastrak switch works fine and continues to work fine.

I did ask support if I can purchase an RTR power supply  separately to run with the Explorer - I would be happy to work with that. Waiting for them to advise ...

Hope this helps!

ryoung3 posted:

Thanks for the update MTH ...

I have a very simple isolated Fastrak loop layout with a bypass and powered by the Z1000 brick (conventional ZController). Replacing the ZController with the DCS Explorer only, the forward truck on one of the passenger cars followed the desired direction of the switch, the trailing truck decided to go the other way ... short, fuse blown. The Fastrak switch works fine and continues to work fine.

I did ask support if I can purchase an RTR power supply  separately to run with the Explorer - I would be happy to work with that. Waiting for them to advise ...

Hope this helps!

Can you tell me exactly what you had connected to the track when the fuse blew and damaged your Explorer?  Did you have the Z-1000 brick (pwr supply only) plugged directly into the Explorer or, was the Z-1000 brick plugged into the Z Controller then, the Z Controller connected to the Explorer?  By any chance did you have two different power connections to the track? 

If the Z-1000 brick barrel jack is plugged into the Explorer you would have ~18VAC fixed on the track.  In this scenario, we've not seen fuses blow or damage occur to the Explorer other that what has been reported on  this forum.  

Please help me by clarifying exactly how track power was connected.  Thanks.

Just to chime in, since I started this thread, I had two passenger trains on two independent loops with a z1000 directly connected to the DCS EXplorer WITHOUT going through a Z Controller, when a passenger car derailed and it blew the fuse. 

I was certain the Z1000 would trip so I did not rush to cut power to the Explorer.

But the z1000 did NOT trip, and the fuse blew. The DCS was not damaged, however. A change of fuse and it was good to go.

MTH - Yes, Z1000 barrel connector plugged directly into the Explorer ... I just swapped out the ZController for the Explorer.

Yes - I have more than one power connection to the track - I use an MTH terminal block and run a star pattern using 16 gauge stranded

Thanks guys. 

Yes, PDX, I understood you blew a fuse with only the Z-1000 but, didn't damage the Explorer.  While surprising, I consider this some fringe dynamic.  The Explorer somehow missed the short for long enough that the fuse blew.  As I have mentioned, partial or intermittent shorts are the worst!  A dead short is much easier to deal with.  Wheels scraping down the rails can be a tough one.  The fuse did it's job in your case.

In the case of RYOUNG3, the concern is how the Explorer broke.  The fuse blew but, the spike was big enough to damage something.  We'll take a look when we get it back here.  This is the only known case of this to date.

Thanks again to both of you.

Comment on an old post.

To be safe, I've added an inline 5 amp fuse to the explorer from the transformer I use, and another one, along with a TVS diode on the output. The fuse to the track will blow occasionally on a derailment and have never blown the fuse in the explorer, which is something I'd prefer to see. Would rather protect the device than have the device protect itself.

But then, maybe I'm just paranoid. 

I have had the same thing just last night. but I am having a hard time removing the fuse, any ideas as to how to get the fuse out?

I use pliers.