FIRE in power module

[Brian Womersley]

I am writing this post because I cannot contact Armortek due to their holiday shutdown AND as a warning to other builders who have the new power distribution module.

I had installed everything from the options packs and everything was working correctly….

Yesterday I switched on the main power switch to activate all systems and there was a sudden sparking sound, followed by smoke, followed by FLAMES… all coming from the main 24 volt input socket into the power module.

Luckily, I was able the quickly switch off the main switch and blow out the flames . Once over this shocking experience, I could see all the burning had come from just inside the module main input socket which was all black and smelt of smoke which it still does.

I can only presume there was an internal short in the main socket. BUT I must ask… WHY IS THERE NO FUSE between the 24 volt batteries and the distribution module… in fact it states on its back that the 24 volt input is NOT fused.

Pending a response from Armortek, I would strongly advise all builders to install an inline fuse or circuit breaker, possibly 50 or 60 amp rated to protect you model. If I had not been present when this short occurred, I dread to think of the consequences.

[Ray Massa]

Brian, so sorry to hear about the power issue. Putting a fuse in line with main power is certainly something I had already planned and have the parts on order. I am still bench testing since I don't have Module A yet, but it will be installed before everything goes in the tank. It is also just a protection should the battery leads touch while installing components. That is a lot of current on a direct short.
Since the Module A and B outputs are not fused, did you see any issue with either audio module or the motor controller? The motor controller especially, since it is capable of supplying 60 amps. Did anything start up before you saw sparks, or was it instantly when you powered up?

-Ray

[Brian Womersley]

Hi Ray….. It was a direct short under the input socket within the power supply module…. Transmitter was on and all switches/controls were off or neutral. It was instant as I switched on the battery switch…nothing had been getting warm on previous operations… there is no evidence of any other shorts anywhere… the full wack of the 24 volts got as far as the socket and hence flames from the input socket .. the power module does not have a warranty seal on it so if Armortek will get in touch maybe I will look inside
Brian

[Jerry Carducci]

It is concerning to read of this. I realize problem can crop up with anything but with the size and capacities of the batteries used for these models they could cause some serious problems if shorted and it's irrespective the battery type used. I didn't put a circuit protection inline with the batteries in my halftrack but I did with my M3 Lee- the difference being the nature of the model. In the Lee the battery, a larger LiFePo4 is pretty much buried in the model and takes some time to get out and in the halftrack they're in the engine compartment. For the Lee I made a control 'box' that sits between the battery and the control modules. It's purpose is to not just provide some additional protection from the battery in the form of a 30amp circuit breaker but also I run the drive motors through a switch that allows me to selectively turn just the motors off so I can test the rest of the model's functions without fear that it will leap off of whatever I have it on. The control box also has a rotary battery shutoff switch of a type orhers have used here.

I maintain a very healthy fear-respect of these large batteries.

I plan to make a similar control box for my King Tiger.

Again very sorry to hear you had this experience and I hope when Armortek determines the root cause we'll all be able to know what that was.

Jerry

[Ray Massa]

Agree 100% Jerry. I am also going to install a Master switch, in addition to a fuse, between the battery and the power cable going to the power supply. I know there is a relay controlling this, but if for some reason the relay contacts short and weld themselves closed and stay full on, I want a method to quickly shut the power down. The fuse should protect against this from happening, but I like redundancy in vital systems where possible .The switch I have ordered is a push/pull type and plan to place it on the outside of the tank and hide it so I have a safety switch (emergency kill) should the tank lose control. I don't want to have to flip up a grill cover and try to hit the Armortek switch. At least that is the plan. Maybe being too cautious, but these things could hurt somebody if they get 'loose'.

[Nick Chiocchio]

Brian so sorry you experienced that. I had a computer grade capacitor explode right under my chin when building a power supply for an audio amp. No fire but the bang unsettled me for quite some time. When something with electrics goes wrong it can be very disheartening because things just blow up, smoke or catch fire.

Anyway; my power module for the Pershing does not look like your unit. It has one 15 amp fuse not all the fuses your unit shows. I'll post a picture tomorrow after work. Did Armortek change the module? Maybe you have the wrong one? Did it work before or did this happen the first time you hooked it up?

I'm getting ready to hook up all my electronics and was planning on test run next week end. I think I will wait a bit.

[Ray Massa]

Nick,

I have the same type/style as Brian. Tom Miller has the same type as you. I wonder how many of us Pershing guys have the new style. Sounds like it was a running change. I was thinking earlier today that something like a shorted electrolytic filter capacitor might do the damage, as it would draw excessive current across the two poles, before popping. So your comment regarding your audio amp issue is right along the same line. I would guess it is a switching type power supply since it is so light (no heavy transformer). Hopefully we will be able find out exactly what happened to it when Armortek takes a look at it.

I do not have Module A yet, and that is one that can potentially draw a lot of current for the motors, but all other motors, linear motors and servos are functional on my test bench and working fine so far. But I will be installing a fuse right off the battery later this week.

-Ray

[ChrisWahl]

I guess I am not alone with motion packs on fire. I posted my recent experience in the motion pack forum.
Mine was just the motion B pack which is for connecting the turret turn and elevation motors.
It is very disconcerting having something burst into flames. At least mine happened when I was bench testing it. I can’t imagine what would have happened in the finished model.
Makes me wonder about continuing with it.

[Brian Womersley]

OMG Chris ….. Yes, it certainly is scary when you get flames and smoke…..
Again … module B is NOT protected by any fuse or circuit breaker…. My power supply module was inside the tank when it caught fire…. Lucky I was present and able to switch off almost instantly…. My heart was racing…
These modules NEED PROTECTION BY FUSE OR CIRCUIT BREAKER and in addition I would be happier if the terminals on the RELAY were not exposing bare terminals below the yellow spade connections
Brian

[Gerhard Michel]

Well, I fear this will not be a useful advice for the most modellers, but I use only self-made wiring to connect all components in my tanks, and I never forget to install an automatic circuit breaker ....

[ChrisWahl]

I would think there is some defect in the design and construction of these units that has two recently purchased packs burst into flames.
It was quite scary having the unit burst into flames the smoke alarm going off and the scramble to shut off the switch and blow out the flames without spreading.
I guess I was under the assumption that the motion packs were “plug and play” without having to re engineer the wiring systems to incorporate protection measures into the system.

[Ray Massa]

I guess I am not alone with motion packs on fire. I posted my recent experience in the motion pack forum.
Mine was just the motion B pack which is for connecting the turret turn and elevation motors.
It is very disconcerting having something burst into flames. At least mine happened when I was bench testing it. I can’t imagine what would have happened in the finished model.
Makes me wonder about continuing with it.

So I did quick check on current draw for the elevation motor. Will do one for the turret motor as well. Both run on 24v max and speed of course is controlled via voltage output.
The elevation linear motor runs at about 12v at medium speed and full 24v with full on. It draws about 125 ma on a slow elevation and 250 ma at full speed. However, if you run it to end of its limit points and stall the motor it will draw .5 amps continuos. Not huge but I make sure my output Channel will be set to neutral after moving it so it will never stay in a stall position.

[Brian Womersley]

UPDATE….. Armortek are now back from annual holiday and I have made an appointment to call in on them this Thursday morning … it’s a fifty mile drive each way, but hopefully worth it to get some explanation of the cause of this fire and take home a replacement module under warranty so I get to resume my delayed build .
Watch this space

[Brian Womersley]

Further UPDATE…..

As stated I called in on Armortek last Thursday…
Kian was reluctant to let me have a replacement power supply module until he had chance to examine the burnt module. After a lot of persuasion he agreed and I took a new one home.
I am awaiting a report of the cause of the fire.
The New module has now been installed along with a 60 amp circuit breaker and an isolator switch. All systems are up and running with absolutely no visible cause for the fire.
The shock of the flames left me very nervous but I am pleased to say I am back to enjoying the next stages of my build. ( with a fire extinguisher on the work bench)

[Brian Womersley]

Looks like Armortek are not going to post a response or explanation of what caused my new style power module to burst into flames.
I have heard nothing from them, and there was I considering placing an order for the Leopard in a few months time . The fire still haunts me.’