circuit breaker question

I hope this is the right group for this question.
I have been running two electric heaters (the ones that look like a radiator) for 3 or 4 years, one in the kitchen and one in the bathroom.
They are on different circuits.
I have never had any problems but 2 weeks ago, they both tripped their breaker at the same time. I reset the breakers and haven't had a problem since.
I am just curious as to what could have caused it. Could a low voltage surge have come in from the power company and caused them to do this.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The two circuits probably share a common neutral, which is loose.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Or the elements are shot and shorting req

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Rich. wrote:

They are separate breakers in a 200 amp breaker box and it's now a month later with no problems with either heater.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

What seems more likely is that the voltage went high long enough to cause excess current flow that exceeded the breakers' trip points.
-- Tom Horne
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Polytechforum.com is a website by engineers for engineers. It is not affiliated with any of manufacturers or vendors discussed here. All logos and trade names are the property of their respective owners.