Triac Identification

Thread Starter

draw2build

Joined Nov 25, 2022
21
I have a coffee roaster that has two triacs and one of my roaster's heater doesn't turn on. I've attached a pic of the specs.
The triac that's connected to the heater T2 (terminals A1 & G), on the diode setting of the multimeter, reads .072, and the other triac T1 reads .037.

The triac numbers are:
BT136600E
PJd1520 A2
0209

I'm seeing triacs on Amazon that has the BT136600E, but the other numbers are different.
Can you please help me identify what numbers I actually need to purchase a new triac?
With T2 reading 0.72 and T1 reading .037, would this mean that the T1 triac is bad?
FYI - Both heating elements tested the same: 5.8Ω. So, one of the heating elements probably hasn't failed.
Quest Roaster.jpgQuest M3s Triac.jpg
 
Last edited:

JohnSan

Joined Sep 15, 2018
42
That's a very good photo.

But why do you think the triac is faulty?
The circuit diagram shows two heaters in parallel.
If one of them is working ok, it can't be the triac at fault.
 

Thread Starter

draw2build

Joined Nov 25, 2022
21
I have replaced the two potentiometers, no success, I replaced the ammeter, no success.
After testing both heaters, and they both had the same ohms, I'm trying to determine why one of the heaters will not turn on. None of the other components look burned, so I'm kind of lost.
 

sagor

Joined Mar 10, 2019
927
If you measured the heater ohms while removed and they are good, then the only reason why one heater will not come on would be that a connecting wire/connector to one of the heaters is broken (or wire is burnt). Switch the heaters around, if the other one works, then it is 100% the wiring to the other that is at fault. There is no other real explanation for 2 identical heaters in parallel to have only one work...
 

Thread Starter

draw2build

Joined Nov 25, 2022
21
If you measured the heater ohms while removed and they are good, then the only reason why one heater will not come on would be that a connecting wire/connector to one of the heaters is broken (or wire is burnt). Switch the heaters around, if the other one works, then it is 100% the wiring to the other that is at fault. There is no other real explanation for 2 identical heaters in parallel to have only one work...
I tested the heaters while they are connected, and the unit's unplugged. Would it make a difference if the heaters are not attached? Could the ohms change?
 

sagor

Joined Mar 10, 2019
927
Yes, if one heater is open, you cannot tell by measuring in circuit, you are reading 2 in parallel and don't know the resistance of just one of them.
In your case, I would now suspect one of the heater elements is open (burnt out). You have to disconnect at least one of them in order to compare their resistance.
 

Thread Starter

draw2build

Joined Nov 25, 2022
21
Yes, if one heater is open, you cannot tell by measuring in circuit, you are reading 2 in parallel and don't know the resistance of just one of them.
In your case, I would now suspect one of the heater elements is open (burnt out). You have to disconnect at least one of them in order to compare their resistance.
This is great to know. Thank you for the reply. I'll get on this tomorrow. Have a great night.
 

Thread Starter

draw2build

Joined Nov 25, 2022
21
I've removed the heaters and tested each.
The first heater reads 5.8Ω and the second has no movement.
Does this mean the second heater has failed? If so, I'll order two new heaters.

Thank you everyone for your help.
 
Last edited:

sagor

Joined Mar 10, 2019
927
Yes, it means the one heater is open, burnt out. Best to replace both at the same time. The open circuit one also seems to be more deformed, which often happens when it develops a hot spot as it burns out
 
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