A couple of weeks we purchased a house built in 1981. First time we tried to cook something in the oven, we heard a loud pop from the wall, so I flipped the breaker and decided to take a look. What I saw after removing the outlet is this:
The outlet is a 50A 3 prong one.
Judging by the stains on the wall, looks like something was spilled at some point and the outlet shorted.
The oven terminal was not in a great shape either:
Judging by the corrosion, it went bad a while ago.
The questions are:
- The fact that the breaker didn't flip on its own -- is it a cause for concern?
- Is this replacement still in DIY territory? I have replaced a few outlets in my life but never had to strip the wires or do anything on a 240V outlet. I have also have never seen weaved aluminum(?) neutral. I suppose I should just try to snip it.
- There doesn't seem to be any ground in the box, but would it make sense to have a professional upgrade this outlet to a grounded one while we're at it? We are planning to use an induction oven with this outlet, but from what I understand the power requirements are the same. Current range "Minimum Circuit Required" is 40A, future range "Required Power Supply" is 40A. Both manuals have same sections on wiring up a 3 wire receptacle with two hots and a neutral.
TL;DR: based on the answers the best course of actions is to have such 3 wire outlet properly grounded and replace the twisted aluminum with copper wire, which is what I ultimately did. Spend a few bucks on a professional electrician -- save a few on a professional mortician.