Blew a fuse on a tower crane in Houston yesterday because I ignored a weird sound

I was lifting rebar bundles at a job site off 45 when the hoist started grinding, then pop, everything went dead. Turned out the brake was dragging and overheating the motor, cost me half a day waiting for a service guy. Has anyone else ignored a noise and regretted it?

3 comments

3 Comments

emery9651mo ago

Yeah, totally been there. @king.lisa nailed it with the thermal overload relay thing, that's exactly what caught me off guard before. The brake drag builds heat so gradual you don't notice til the whole system shuts down.

anna_hill1mo ago

You know what nobody's brought up yet is the cooling fan on the brake motor itself. If that fan is clogged with dust or debris, it can't pull air through the motor windings, so even a tiny bit of brake drag turns into a heat bomb way faster than normal. I had a guy ignore that for three months on a warehouse jib crane and the motor windings literally fused together from the heat buildup. The thermal relay might not even trip if the overload is just barely there over a long period, it's sneaky like that. Definitely worth popping the fan cover off and checking for gunk before you go replacing anything expensive.

king.lisa1mo ago

Was the grinding sound constant or did it come and go? I've dealt with a few crane motors on residential jobs and the worst failures always started with a noise that seemed to stop when I throttled down. Like one time on a Liebherr, the brake shoe was catching just on the low speed creep and I wrote it off as wind noise. You might want to check if the thermal overload relay tripped on the motor control panel, not just the main breaker. A dragging brake usually leaves a lot of heat discoloration on the drum, did the service guy mention anything like that?