Fuse blowing at start-up

[emergent]

We have a Puma 6s. We turn the switch on at the back at computer cabinet but when we press the machine ready button it throws a breaker in the cabinet. The breaker is marked QF24. I have not been able to locate this breaker or the components associated with it in the electrical ladder diagram. The machine alarm is indicating a short. The breaker is a 7 amp.

[Al_The_Man]

Check the wire numbers, if any that are connected to the breaker and see if you can identify it this way from the schematic.
Marked QF24, it may be a 24v breaker, see if you can identify what general circuit it is supplying by tracing the conductors.
Take a voltage reading from the high side of the breaker, should tell you at least the voltage, ac/dc etc.
Al.

[techman1]

Your post is a month old. Did you ever find your problem? What is the wire number coming off of the breaker. I would suspect a shorted hydraulic solenoid coil. I could help you with more information. Try going to the bottom of the ice-cube relay boards and read the resistance of each solenoid til you find one shorted. If you never use the tailstock, see if the tailstock quill retract solenoid is burned since it sits there and cooks forever. To see the solenoid coils, just remove the retaining nut and slide the whole copper colored can off the solenoid shaft and pop the can lid off.

[techman1]

I remembered a needle in a haystack find on a machine doing what yours was doing. The braided cable cover was pulled out of the chuck open/close footpedal and the wire insulation was dried out and cracked away and getting 24 volts to ground right there. I just taped the wires where the insulation was missing and reassembled the strain relief connector at the footpedal.

[emergent]

I've been directed to the solenoids on the chuck hydrolic. I haven't been able to do any more diagnostic on this machine due to other higher priority machines needing work. Thanks for the reply's, & I am going to look into each one asap.