SMC Plus Burnt Components

Hard to say without a circuit diagram.

Could have been an over voltage event (or events over a period of time) on the power line or a component failure resulting in multiple components being damaged.

How old is the starter and have you had any storms or power quality issues?

Hi Jack of AT, thanks for your immediate response. Out Starter is about 10 y.o.

Not subject to transcient voltages nor water splash. It operates 24/7 on normal Process operation, ON / OFF switching to aprox. 50 times during 24 hour cycle. Sorry to say, cant provide circuit diagram.

antiquo

It sounds like it may just have reached its end of life and failed due to excessive component value drift and/or component failure. Electronics don't last for ever after all (especially capacitors).

It is very likely that after 10 years of being powered, and continuously switching, some components started to deteriorate. Transformer winding insulations for one will be degraded due to variations in heat and surrounding humidity. Usually they are the most vulnerable to environmental effect, and first to fail. Due to degradation and as the inter-winding starts to develop shorts then arcing. Other immediate components will follow due to excessive current drawn which may eventually lead to either the fuse blowing or an electrical fire due to arcing or heat!

Board replacement is in order!

Good luck..

Simple. The burnt equipment has passed more current than it was intended to withstand and the circuit protective device(s), if any, were inadequate to prevent equipment failure.

A.K.A. heat :)

I can't see the caps in detail - are you sure some aren't slightly bulging?

Loss of one component can cause cascading failures.

Without circuit diagrams it is really hard to guess what happened.

Excessively high temperature caused by high electrical current and/or high ambient temperature and/or loose electrical connections and/or component failure.

Many applications experience excessively high ambient temperatures and subsequent failure because the enclosure is not vented and there is no way for the heat generated by the equipment to exit the enclosure.

The closer to system design operating limits that the equipment functions, the more heat is generated by the system dynamics.

This equipment generated heat is magnified by high ambient temperatures and high relative humidity.

The result triggers a cascading event wherein the temperature exceeds the allowable equipment temperature rise allowance and the level damage incurred is additive over long periods of exposure.

Accumulation of contaminent such as lint, dirt, and chemicals add to the issue so adopting and executing a regular PM that keeps the equipment enclosure clean is priority.

I would thoroughly clean the enclosure and if vented make sure the vents are open and the exhaust fans (if present) are operating properly.

If the enclosure is sealed, I would put a temperature recorder inside it and monitor the temperature over a period of time wherein the equpment is operating at peak demand.

If the recorded temperature reaches 95% of rating, I would install a cabinet cooling system sized accordingly.

Amazingly similar to the damage done here to one when someone (remaining unnamed) thought the test center transformer was set to 240V when it was in fact set to 400V. (was there a big bang when this occurred?) How stable is your electrical power supply?

Just curious, are the tyristor & triac mounted on heat sink?

If they are for switching purposes on the power supply, aren't they best to be mounted on heat sinks?