Went to jump out a water source heat pump today using R to Y1 (the maintenance guys would of had to start it using their automated system, and they typically don't want to be bothered). It still wouldn't energize so I decided to take the jumper off (with 460 volts still flowing through). One side of my beautiful little magnetic jumper wire (those $10 yellow ones) popped off and instantly stuck to some other metal, apparently grounding the transformer. Sparks and smoke...kicked the breaker....so I ended up bothering the maintenance guys anyway (didn't know where the breaker box was).
Hope this makes your day seem a little less worse.