Yaskawa has sold its Sigma servo systems in several generations, and machines built over twenty years carry all of them. The model number on the rating plate tells them apart: the letters after SGD (the amplifier, which Yaskawa calls a SERVOPACK) and SGM (the motor) name the generation, and the rest names the rating, the encoder and the options.
Reading the generation from the model
| Generation | Amplifier (SERVOPACK) | Motors |
|---|---|---|
| Sigma (the first) | SGD-, SGDA- | Not covered here |
| Sigma-II | SGDM-, SGDH- | SGMAH, SGMGH, SGMSH, SGMPH |
| Sigma-III | SGDS- | SGMxS (for example SGMPS) |
| Sigma-5 | SGDV- | SGMxV (for example SGMJV, SGMGV) |
| Sigma-7 | SGD7S-, SGD7W- | SGM7x (for example SGM7A, SGM7J, SGM7G) |
The pattern is consistent: H for Sigma-II, S for Sigma-III, V for Sigma-5, 7 for Sigma-7. Search by the model you have: a search for SGMAH finds Sigma-II motors, not their Sigma-5 relatives.
The migration path Yaskawa publishes
Yaskawa’s product transition tools include a Sigma-II to Sigma-5 conversion guide (PL.Sigma-5.01), a Sigma-5 to Sigma-7 transition guide (14H-001), a note on CN1 connector options from Sigma-II, LEGEND and Sigma-III to Sigma-5 (TN.MCD.14), and mounting adapter plates for Sigma-5 SGDV amplifiers (TG.MCD.11.421). Read them before you change generations: the connectors, the mounting and the parameters all differ.
The integrator Cross Company has published an account of a migration of 300 axes that went from Sigma-II to Sigma-7 in stages, with Sigma-5 as the stepping stone, because the direct step was not practical for that plant. Your machine may be simpler; the point is to plan the step, not to discover it on the night of a breakdown.
When a spare of the same generation is the fix
If one SERVOPACK has failed and the rest of the machine runs, a unit of the same model is the shortest way back: same connectors, same mounting, and the parameters from the old unit or the machine builder’s backup. The migration can wait for the next planned shutdown.
Searching Sparehawk by generation
Use the prefixes from the table above. Amplifiers and motors are searched separately, so search the SERVOPACK model and the motor model each in full. Yaskawa inverters (CIMR- models) are searched the same way. Each offer shows its condition (New / OEM, new surplus, refurbished or used), the supplier’s country and the lead time.
Search for SGDM, SGMAH, SGDV or browse all Yaskawa parts.
Before you order
- Copy the whole model from the rating plate, including the suffix after the last dash (
-OY,-E, a custom-Ycode). Custom suffixes mark machine-builder variants, which may have different firmware or connectors. - Note the motor’s encoder. The character for the encoder sits inside the motor model; a SERVOPACK has to match the encoder type of the motor it drives.
- Back up the parameters with SigmaWin+ if the old unit still powers up.
- Ask what “refurbished” covered for this unit. Refurbished, surplus and used explains the conditions, and warranty on surplus parts lists the questions to ask about cover.
No matching offer? Send a request with a photo of the rating plate: how requests work.