Inline fuse keeps blowing

[LamarM]

I've had a Bradley BS611 smoker for about a year now, it has blown 2 fuses over the last 3 months. anyone have any idea why this might be happening and how to fix it.

thanks Lamar

[tskeeter]

Lamar, one of two things is probably going on.  Your heating element is drawing too much power, or the temp in your smoker cabinet is getting too high.  Because this has been an occasional problem, rather than every time you smoke, I'm betting that your cabinet temp is getting too high.

My understanding of the inline fuse is that it's being used as an excessive temperature device.  The way it's installed in my six rack, it looks like it's intended to detect high temperatures, such a from a grease fire in the heating element, and cut power to the heating element in an attempt to reduce the heat and make the fire go out (fires need heat, fuel, and oxygen to burn).

When the inline fuse in my smoker activated, I suspect that the temp got too high because a pork shoulder had bulged as it cooked and came in contact with the temp probe for my PID, which is mounted through the wall of the smoker.  When the probe came in contact with the cool meat, the PID started to read the meat temp, not the air temp in the smoker.  Since the meat temp was below the PID set point, the PID thought the smoker was too cold and it kept trying to heat up the smoker more.  The PID was successful in heating the smoker up to the point that the inline fuse activated (it was easier because of my dual element mod).

I don't know how hot things need to get to activate the inline fuse, but I suspect that it's somewhere around the 300 - 400 degree range, because the normal operating temperature for Bradleys is below 300F (it seems that most won't get above about 270F).

In your shoes, I'd be thinking about what I was smoking when the inline fuse activated, what temp I was using, what devices I was using to control the temp, and if anything could have happened to cause the temperature controller to get incorrect information.

[LamarM]

thanks for the reply, the temp in my smoker has never gotten higher than 250 ever, that's with no meat at all in the smoker. I've suspected that I got a lemon right out of the box because of this. the fuses didn't start blowing until the smoker was a 1 year and 1 week old (out of warranty). I've replaced the heating element but that didn't help, the resistance of both elements has fallen in the correct range according to what I've been able to find on the internet 32 ohms. I'll buy a supply of fuses to keep on hand use it for another year and then throw it on the recycle pile.

Lamar

[tskeeter]

Lamar, don't lose hope.  There are a lot of guys here that are more familiar with the wiring of a BS611 than I am.  And who know a lot more about electrical systems and electronics than I do.  Hopefully one of them will come along soon and be able to help you identify what's causing your problem.

Your smoker worked fine for a year, then you started to have occasional inline fuse issues.  To my mind, I think something changes periodically about operating conditions of your smoker that is causing the inline fuse to get too warm and it activates.  The challenge is to figure out what that change is. 

Thinking about the kinds of things that I do that could cause an inline fuse to activate, I have some questions. 

When the inline fuse has activated, were you doing something that could cause heat from the element to be concentrated against the back wall of the smoker, where the inline fuse is attached?  When I do pork shoulders, I use a disposable aluminum pan to catch drippings.  If you do something similar to ease cleaning, is it possible that the air circulation is getting obstructed and the heat is getting concentrated in an area of the smoker that is away from where you are getting your temperature reading?  (For a period of time, I was having trouble with scorching when I smoked cashews.  Finally figured out that I was putting so many nuts in a basket that it was trapping most of the heat and smoke below the bottom tray of nuts (and below my temperature probe).  Results improved when I reduced the nuts in each basket to allow better air/smoke circulation.) 

What are you using for a temperature sensor and where in your smoker are your temperature readings coming from?  If you have a remote thermometer, it might be worth checking the temp in the area where the inline fuse is mounted during your next smoke to see if your smoker is significantly hotter near the inline fuse vs. where you normally take your temp readings from.

What were you smoking the two times the inline fuse activated?

When the inline fuse activated, was the smoker really full or lightly loaded?  An estimate of the weight of what you had in the smoker would be helpful.

How do you power your smoker?

When you replaced the failed inline fuses, did you inspect the wire it was installed in?  See anything unusual? 

[LamarM]

I was probably smoking a brisket or pork loin (maybe 15 lbs). I always try to place the meat well away from the back wall of the smoker where the sensor is located. I always have to run the temp gauge on the highest position to get the heat up to around 225. I never use a drip pan for anything, I smoke for about 2 or 3 hours to get the smoke flavor in the meat then I usually wrap whatever I'm cooking in tinfoil so it will retain the juices and get very tender so I don't have excess drippings. I don't heavily load the smoker but each of the 4 shelves has meat on them usually. I have a wireless temp gauge with a probe for the meat and the temp gauge on the smoker for smoker temp (it's off by about 20 degrees) I buy the full inline fuse harness for replacement so that I always get new wire. the wire on the one that I replaced a couple of days ago looks like it has some damage on the outside of the wire on the insulation, but not enough to cause any issues I think. the protective tube (I'm assuming that it's some type of heat resistant material) has some scorch marks on it), but again I don't believe it's enough to cause issues. I am curious what the rating is on the thermal fuse

[tskeeter]

Lamar, I assume that the protective tube that you mention is the tube that covers the inline fuse, in the middle of the red wire.  If so, I expect that the marking your are seeing is related to the fuse activating.  Regarding damage to the insulation, can you tell me where the damage was in relation to the end of the wire with the round lug on it?  Wondering if the insulation on the wire is getting damaged where it goes through the back wall of the smoker.

Following the idea that something is damaging the insulation on the red, hot lead to the heating element, do you move your smoker in and out of storage between uses?  Or is it sitting some place where it might be subject to vibration?

[beefmann]

you  may have a voltage leak to ground  someplace from moisture,.. it could be  jut about  anywhere.... if you   have a  ohm  meter start checking your  cabinet,,, you  will have to  disconnect  the  items to  check them to  ground,,, ( the  case  ) then reconnect if you  do  not get a  reading... also if a  bare wire it touching  the  cabinet  it  may  not always  be making  contact though  with vibration it may and will be  enough to  pop the   fuse...

This may be a good  place to  start do a good ohm check to  ground through out the  tower and  smoke  generator

also are you   running your smoker on a  gfi protected receptical or circuit?

[Orion]

Fuses are designed to limit the amount of current moving in a particular circuit. They are a safety devise to prevent fires and damaged wiring due to dead shorts. Current flowing through a resistor, (element) is limited by the rating of the resistor. Fuses generally burn out when there is a direct short to ground within the circuit or a fuse of insufficient capacity has been installed.

Are you sure you replaced the first failed fuse with the correctly rated fuse? If so, check your wiring for damaged insulation, any signs of arcing or poor connections: dirty, oily, corroded and then check the resistance of your element against factory specs. Also check the physical condition of the fuse terminals. I would hazard a guess your element is bad.