Faults on the 300Hz spindle circuit have proved to be very difficult to trace. There symptoms are quite straight forward, but failing to find the real root cause has created huge costs in revisits and destroyed components. It is vital that all root causes are examined and eliminated, as there is often more than one root cause and very often they are intermittent.
Technical Bulletin
| TB Number: | 238 | |||
| Originator: | Gareth Green | |||
| Machine: | High Speed Spindle Ring | |||
| Date: | 27/11/13 | |||
| Circulate to: | Service | |||
| Title: | Fault Finding 300Hz Spindles | |||
| Version Info | 1 | GG | 27/11/13 | Original Version |
| 2 | GG | 17/07/14 | CUB inverter issues; DC Injection braking | |
| 3 | GG | 04/08/14 | Soldering of termination on Ring connection
Relay PCBs Mechanical interlock on 50hz / 300Hz Resistor value on CUB / VXM | |
| 4 | GG | 25/02/16 | Illegal spindle control commands in mnd file | |
Detail
Faults on the 300Hz spindle circuit have proved to be very difficult to trace. There symptoms are quite straight forward, but failing to find the real root cause has created huge costs in revisits and destroyed components. It is vital that all root causes are examined and eliminated, as there is often more than one root cause and very often they are intermittent.
Symptoms
| Code | Description |
| SP001 | Elte Spindle Overheating / Smoking |
| SP002 | Tools Breaking |
| SP003 | Spindle not plunging or not fast enough |
| SP004 | Tool Stalling While Cutting |
| SP005 | Spindle Not Starting |
| EL003 | Inverter Smoking / Exploding |
| EL001 | Main Fuse in Factory Trip |
Actions / Checks
| Code | Description | Tick |
| CHK_CL001 | Check for evidence of water in electrical cabinet | |
| CHK_PA001 | Check Inverter Accel / Decel Parameters match front end. See TB234 | |
| CHK_PA002 | Check Inverter Parameter Settings
Particularly F20, F21, F22 MUST BE ZERO |
|
| CHK_PR001 | Check Profile is not wet when put on machine | |
| CHK_SP001 | Check connections in spindle motor terminal boxes. Check for stray strands of wire or any evidence (Blackness / smell) of arcing to case. Check for nuts or washers floating around | |
| CHK_SP002 | Check Elte Motor connection nuts by removing and refitting
(The lower nut has been found to be loose in many cases) |
|
| CHK_SP003 | Check cables for insulation damage under shrink wrap as it enters Elte motor.
(The inner core is often cut into when outer sheath originally removed) |
|
| CHK_SP004 | Check ring cables and energy chain for damage. Be thorough. Disconnect and pull it all out. Check the ring plug for arcing | |
| CHK_SP005 | Check spindle plunges freely on slideways | |
| CHK_SP006 | Check inverter alarm input is working and enabled in alarms | |
| CHK_SP007 | Test on windings of each spindle motor for equal resistance across each phase pair | |
| CHK_SP008 | On ZX/ Microline, check 300/50 Hz Contactor function for bad / welded phasesCheck that the mechanical interlock is fitted and working to mechanically prevent both relays switching on | |
| CHK_SP009 | Check Spindle (Shrack) relay and base for blackened / welded contacts and check all 3 phases make contact
On ZX / Microline check each of the Spindle Card relays for full on / off function of each phase relay (requires removal). Check for signs of blackening or PCB damage, particularly if the relays have been desoldered and replaced |
|
| CHK_SP010 | Check Inverter breaking resistor is fitted and is correct value –
160R on VXM, 2 x 100R in series on CUB |
|
| CHK_SP011 | Check Spindle Card relays are all functioning - 3 contacts all off and on | |
| CHK_SP012 | Check Spindle Tool Plunge sensore fitted and working | |
| CHK_SP013 | Check cutters/ sawblades are not blunt and are Stuga branded | |
| CHK_SP014 | Check direction of spindle motors | |
| CHK_SP016 | Check for water in spindle motor | |
| CHK_SP018 | Check for trapped wires under spindle access covers | |
| CHK_SP019 | On a Flowline Mk3 ring refurb upgrade, check the 50Hz / 300Hz changeover relay | |
| CHK_SP020 | On a Flowline Mk3 ring refurb upgrade, check the feedback wire has been fitted and alarm has programmed in front end. See TB0219 | |
| CHK_SP021 | Check Ring connection (green connector at top of ring) plug solder joints – particularly under heatshrink – cause of failure on M006 | |
| CHK_SP022 | Check mnd files for legacy ou.SMOT commands. This is a legacy issue that overcame software problems, but on all winMulti machines, dp.n=off or dp.n=half should be used (n is the spindle number). Using SMOT in the wrong way creates the wrong sequence of events |
Historical Inverter Issues
There have been 5 types of inverter used.
1. Jaguar CUB
This was the original inverter. It is not capable of switching two types of motor and is used in 300Hz mode only on ZX machines up to Z025 and Microlines up to M009.
The original design intent was to use “DC Injection Braking” to try decelerate the spindle motors quickly. This was not particularly effective.
2. Jaguar VXM
The CUB was upgraded to a VXM to give better deceleration control. The drive company (IMO) was tasked with designing the best possible system to decelerate two Elte 0.75kW motors to standstill in less than 250ms. IMO specified the new value dump resistor (160 ohm). The “DC injection braking” is not used.
In later designs, including the Flowline Mk3 High Speed Spindle Upgrade and new Autoflows, the inverter is used to provide dual frequencies (50Hz for V notching and 300Hz for Spindles).
3. VACOM
This was only used a handful times as it was superseded by the Delta
4. Delta
The Delta was chosen because it had a PLC on-board which allowed some signal processing. This was to allow the inverter to change the overload current if more than one spindle is used in a double plunge scenario. Previous to this change, the overload value was set to 2x the peak current, which created the issue of quickly burning out spindle motors in an overload situation
Regrettably, these inverters proved very susceptible to short circuits or missing phases, and tended to fail spectacularly with no idea of the root cause of the fault. They are being replaced with Yaskawa inverters when they fail.
5. Yaskawa
The Yaskawa has proven to be much more bullet-proof in short circuit scenarios. It also has a small PLC code facility and has been programmed with an output signal to indicated back to the PLC that the deceleration phase has finished. This is used to ensure there is no residual current when the relay contacts are opened, which causes blackening of the relay contacts.
Parameters B2 -02 and B2-04 set to 0
Important Changes On winMulti Upgrade
If a windows upgrade is carried out on a CUB inverter system, two very important changes must be made to the parameters settings
1. All DC injection braking parameters in the CUB inverter (F20, F21, F22) must be set to zero
2. The CUB is not capable of deceleration as well as the VXM, so the deceleration parameter (F08) should be set to 0.6, and the winMulti parameter ps_InvDecel300Hz should be set to 600
Draft
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