Septic Alarm Shorting out

[Andreas638]

The alarm to my septic tank (the alarm to the tank with floats: the alarm communicates with the floats for high and possibly high/low level conditions) is shorting out. The alarm has 120V going in and low voltage going out. I know it's a short because the low voltage out wire - the low voltage wire out of the alarm control box (~ communication lines to the floats) gets extremely hot and immediately trips the 20A breaker governing the outlet. The breaker tripping occurs within a few seconds of plugging the unit into the 120V outlet.
I suspected the stepdown transformer on the circuit board was bad so I replaced it. No change: plugged in the alarm and the circuit breaker blew and the low voltage lead out of the box got extremely hot (clear sign of a short, I think). The transformer did not even get warm so now I'm thinking it's something else...I know nothing about electronics, however. Is there a component (capacitor, resistor, something) that protects the transformer that could have gone out, rather than the transformer itself? (the transformer is small and pin mounted to the circuit board in the control box)
I've checked the internal wire connectors in the control box and cannot find a loose or crossed wire in the box. Several hundred dollars to replace the alarm and it may not even be the alarm...
Any ideas much appreciated!

 

[hevans1944]

Bite the bullet and replace the alarm. Hire an electrician (a lecky in Australia) or a septic tank service to troubleshoot and repair this. You are clearly unqualified to be "messin' around" with things connected to household wiring, as demonstrated by your "shotgun" approach to replacing the transformer without a single diagnostic procedure to determine whether the transformer was actually faulty. That sort of "troubleshooting" technique disappeared when vacuum tubes and tube sockets vanished from commercial electronics such as radios and television sets.

 

[Andreas638]

Yes, you are probably right. However there is more information to relate. I had called the septic company that had their name on the alarm control box and they would not sell me a new alarm directly but referred me to their dealer network which marked up the alarm costs by 80%+. The box had already been marked up substantially at the manufacturer (the components are worth about $35 wholesale) Then I found out the septic alarms were not even manufactured by the septic company but by a third party, but could not find out which third party manufacturer. Meanwhile, the alarm box was shorting out...the stepdown transformer function was not operating properly, but rather high voltage was being passed through the box to the low voltage lines, causing the "hot LV wires" and the circuit breaker to trip immediately, presumably limiting any damage downstream. This HV pass through occurring led me to believe the transformer was out; also, the septic company technician I spoke to on the phone also said the transformers on the control boards were somewhat fragile, being subject to failure after power fluctuations, which we have had several in the past year. Based on this information, it seemed that replacing the transformer was a logical place to start. Crossed, loose wires another place to look, did not find any.
Transformer not doing its job or current not passing through transformer for reduction (stepdown) is what was the logical first place to look. This electronics board is intended for people to get reliable advice even though I don't mind well intended criticism. In seeking such advice, what would be the next place to look? I have ordered another alarm, same manufacturer as the float control switch out at the tank, so hopefully they will communicate, but it will take a while to arrive. The new alarm does not have the exact same wiring set up as current alarm control box so it's not a turn key replacement. Though same manufacturer as the float control sensor it has to communicate with.
I usually keep working way too long on something until I get it, however. Probably a simple explanation/answer I am not seeing yet. Any further advice on the alarm transformer issue described above appreciated.