What thermal fuse do I need.

[renerelire]

Hi !
I need to replace a thermal fuse (I know what causes the fuse to burnt), but I'm not sure what to buy. For instance, I found some that said on it : "250V". Is that ok for a 120V appliance?

Electric Hot Plate
Model : SB-01
1500W, 120V, 69Hz

What it is written on the original thermal fuse:
MICROTEMP
ZG JAEZ
G A 4 0 0
TF 216C

 

[Harald Kapp]

Using a 250 V fuse in a 120 V circuit is o.k., just not vice versa.

GA400

Sure? I find G4A00 type fuses. The one you have is most likely a 216 °C type. See this datasheet.

 

[renerelire]

Thanks Haral Kapp!
I don't know what to do whit the datasheet.
So, I just need to know the degree, witch is 216C, and the Volts can be 120V or 250V ?
How many Amps does it needs ? 15A? As 1500W / 120V = 12.5A ?
I there a side (a direction) I need to solder it ?

 

[ratstar]

The amps has to do with the rest of the circuit as well, I think you measure the resistance- and that will tell you how much amps goes through. (I think thats partially wrong tho...)

 

[Harald Kapp]

From the datasheet:

G4 Series
Rated for continuous operating currents up to 10 amps @ 250VAC (15 amps @ 120VAC), the G4
series MICROTEMP® TCO is the industry standard for over-temperature protection. The G4 series is
applied to millions of appliances and personal care products each year, providing reliable back-up
protection for temperature controlling thermostats and other over-temperature conditions. The
G4 series is also widely applied in office machines, portable heaters and industrial equipment as a
thermal safeguard.

Fuses have no directionality, solder it any which way.

 

[Bluejets]

I need to solder it ?

Careful there, need to shunt the heat with needle nose pliers or the like otherwise end up destroying the new one.
Most are crimped in place.

 

[renerelire]

Thanks to all, but I still don't know what I must use.
Since my voltage is 120V, I can use a 15 amps fuse with 250V if I don't find a 150V one ?

 

[Harald Kapp]

Of course you can. The higher voltage rating signifies that the fuse can safely interrupt a 250 V line. It will then also be safe on a 120 V line. I stated that already in post #2.
You never replied to my question about the part number being GA400 as per your original post but me finding only G400A types. The G400A, the datasheet of which I also linked in post #2, is good for 15A @ 120 V.

 

[renerelire]

I thought that the G400 data sheet was just explanation about the type of the fuse (for me type means "sort, category") and I said that I didn't know what to do whit it. I think my English is not good enough for this topic.
Is there something I have to do to mark this thread as closed ?
Thanks anyway

 

[flippineck]

Looks like the outer case will remain live after operation if connected one way, but not if connected the other way round. Always wondered what was inside these.

 

[Harald Kapp]

I thought that the G400 data sheet was just explanation about the type of the fuse

No. The main question is: is the old fuse really GA400 as you stated in your post , or is that a typo and the fuse really reads G400A?
If the fuse reads G400A, then according to the datasheet and my post #2 and detailed in #8 it is a 216 °C thermal fuse, rated 15 A at 120 V.

Looks like the outer case will remain live after operation if connected one way,

I always wonder what it is with the (anglo-saxon?) way of insisting on that distinction between live and neutral when it comes to devices with a cable and plug. That may be a suitable way of looking at appliances that are installed permanently when the correct attachment to live and neutral can be verified. Whenever there is a cord and plug, there are at least two reasons not to rely on this distinction but rather treat both wires as if they were potentially live:

1. If the plug isn't coded for direction of insertion (as is the case with many plugs following European standards, but also e.g. American two-pronged plugs), it is a 50/50 chance to predict which terminal will be live and which one will be neutral. So for safety reasons both have to be treated as potentially live.
2. Even if you use coded plugs (as e.g. when an earth terminal is used as in America or GB), you can never be certain that the outlet is wired correctly. If live and neutral are swapped within the outlet, the device will still work fine, but the assumed neutral will be live. So for safety reasons even in this case both wires should be treated as potentially live.

 

[shrtrnd]

In support of what Harald said about treating both wires as potentially live:
Assumedly licensed electricians here in the US wire outlets to the correct standard.
But a lot of do-it-yourself homeowners here replace outlets in their houses (and probably elsewhere, at work and etc...)
without regard to hot or neutral wires. As Harald said, the device will work no matter which way the outlet is wired,
It is unwise to ASSUME live or neutral wires because you can never be sure who did what to the outlet.