Posted By: Vic
Siemens 72K starter fault- "swap leads" - 04/11/12 12:04 AM
I've got this older Siemens motor starter, called a 72K. This was the version just before the ubiquitous 72G. We are all familiar with the 72G, that's the one with the LCD display, and the menus. But the 72K, (the previous verions to the 72G), just had 7 LEDs on the front, and two rows of key data, to interpret the LEDs. If they are solid, the first row of data applies, such as Pwr, Run, Normal Phase, Up To Speed, etc. But if any of the 7 LEDs are flashing, then the second row of data applies, in which case the interpretation all changes to Pwr Flt, EEPROM, Rev Phase, and oddly, something called "Swap Leads". 5th LED down, flashing, means "Swap Leads". Pushing the little red reset button does nothing, the fault remains.
The motor leads read normal ohms to ground and to each other.
At first guess, this "swap leads" fault might mean you have a reverse phase condition, and it's telling you to swap incoming 3-phase power leads. Only this conclusion doesn't hold up, because for one, there is no corresponding Rev Phase fault lit up. We swapped the incoming 3-phase leads anyhow, just to see, but it did not clear up this fault. We did however get a Rev Phase fault, as expected. Futher evidence that "Swap Leads" is not refering to phase rotation, since that Rev Phase fault LED is not lit, while "Swap Leads" is lit.
So the next possibility could mean that it's telling you to swap two of the motor leads, but I'm not sure why it would ask for such a thing. It has no way of ascertaining rotation of the motor itself.
Anybody got a manual? Google search comes up empty, just leads to the newer 72G manual, which is no help at all.
The motor leads read normal ohms to ground and to each other.
At first guess, this "swap leads" fault might mean you have a reverse phase condition, and it's telling you to swap incoming 3-phase power leads. Only this conclusion doesn't hold up, because for one, there is no corresponding Rev Phase fault lit up. We swapped the incoming 3-phase leads anyhow, just to see, but it did not clear up this fault. We did however get a Rev Phase fault, as expected. Futher evidence that "Swap Leads" is not refering to phase rotation, since that Rev Phase fault LED is not lit, while "Swap Leads" is lit.
So the next possibility could mean that it's telling you to swap two of the motor leads, but I'm not sure why it would ask for such a thing. It has no way of ascertaining rotation of the motor itself.
Anybody got a manual? Google search comes up empty, just leads to the newer 72G manual, which is no help at all.