Slip rings
Mercotac Models 430, 630 and 830 slip ring
Multi-conductor liquid-metal rotating connectors combining two 4 A circuits with two, four or six 30 A circuits (Model 830: 8 conductors in total), with the 430 rated 250 V.
Key specifications
| Circuits (max) | 8 |
|---|---|
| Current per circuit (max) | 30 A |
| Voltage (max) | 250 V |
| Voltage note | 250 V published for the 430; not listed for 630/830 |
Summarised in our own words from Mercotac, Inc.'s published data; series maxima, individual models vary. Last checked 2026-10-30. Source 1 · Source 2
Notes on this data
Mercury-wetted (liquid metal) contacts: Mercotac states the connectors contain a small amount of elemental mercury and cannot be said to conform to RoHS; EU users must check exemptions and national rules.
Specify Motion is not affiliated with Mercotac, Inc.. Mercotac and Models 430, 630 and 830 are used only to identify the product. Comparisons use published figures; always confirm against the current datasheet.
Typical applications
Alternatives that meet or exceed these figures
Engineers often come to us with a Mercotac part number and leave with an alternative that is easier to source, quicker to deliver or a better fit for the machine. These 3 series from our supply network are the closest match on published figures.
High-circuit-count slip rings that carry hundreds of mixed power, digital, analogue, fibre and RF channels in one unit.
| Published maximum | Models 430, 630 and 830 | Multi-channel Slip Ring |
|---|---|---|
| Circuits | 8 | 500 meets or exceeds |
| Current per circuit | 30 A | 30 A meets or exceeds |
| Speed | — | 480 rpm |
| Voltage | 250 V | 700 V meets or exceeds |
| Bore | — | 40 mm |
Slip rings using heat-resistant materials for extreme temperatures from -55°C to +250°C, such as hot rollers and heating plant.
| Published maximum | Models 430, 630 and 830 | High & Low Temperature Slip Ring |
|---|---|---|
| Circuits | 8 | 48 meets or exceeds |
| Current per circuit | 30 A | 50 A meets or exceeds |
| Voltage | 250 V | 500 V meets or exceeds |
| Bore | — | 88 mm |
A small analogue power-and-signal slip ring with FASTON quick-connect terminals for fast wiring in dusty, high-cycle machinery. Optional IP65 sealing.
| Published maximum | Models 430, 630 and 830 | HR Series Faston Type Slip Ring |
|---|---|---|
| Circuits | 8 | 8 meets or exceeds |
| Current per circuit | 30 A | — |
| Voltage | 250 V | — |
Figures are the highest published for each series and are not always measured the same way. A higher figure is not automatically a better choice: mounting, duty cycle, feedback, connectors and approvals matter too. An engineer will check the fit against your application before recommending anything.
What a slip ring is
This group covers slip rings that do not fit a single standard format, including modular and split designs, contactless capacitive or optical data rings, temperature-rated units, quick-connect terminal designs, very high circuit counts and application-specific assemblies for wind turbines or packaging. All solve the same problem: transferring power, signals or data between stationary and rotating parts of a machine. What differs is the construction, which may be a split housing, a modular stack, a non-contact data path or a special material set.
When engineers choose a slip ring
Engineers look at these designs when a standard capsule, through-bore or pancake unit does not fit the job. Split rings suit retrofits onto existing shafts. Contactless data rings suit high data rates or long life without wear. Modular units allow circuit counts to change between machine variants. The trade-offs are cost, availability and, for custom designs, longer lead times and qualification. Match the construction to the real constraint, whether that is installation, data, temperature or circuit count.
How to specify the Mercotac Models 430, 630 and 830
Send these with your enquiry and an engineer can confirm the right Models 430, 630 and 830 variant or an equivalent:
- What makes the application non-standard: installation, data, temperature, circuit count or format
- Circuits, current and voltage (A, V)
- Data protocols and rates
- Speed (rpm) and expected life (revolutions)
- Bore, envelope and mounting (mm)
- Temperature range (°C) and IP code
- Terminations, such as flying leads, connectors or quick-connect tabs
Common mistakes to avoid
- Choosing a special design when a standard type with minor changes would do
- Not stating the actual constraint, so the supplier offers the wrong format
- Assuming contactless data channels also carry power
- Underestimating lead time for custom or modular builds
Mercotac Models 430, 630 and 830: frequently asked questions
What is the Mercotac Models 430, 630 and 830?
Multi-conductor liquid-metal rotating connectors combining two 4 A circuits with two, four or six 30 A circuits (Model 830: 8 conductors in total), with the 430 rated 250 V. Published series figures include circuits 8, current per circuit 30 A, voltage 250 V. It is made by Mercotac, Inc.; Specify Motion can help source it or propose an equivalent.
Who makes the Mercotac Models 430, 630 and 830?
The Mercotac Models 430, 630 and 830 is made by Mercotac (Mercotac, Inc.) and is listed here for engineers comparing options. Specify Motion is not affiliated with Mercotac, Inc.; brand names are used only to identify the product.
What is the circuits of the Mercotac Models 430, 630 and 830?
The published series maximum circuits is 8. Individual models and sizes in the Models 430, 630 and 830 range vary, so check the exact variant against your duty cycle, mounting and environment, or ask our engineers to confirm the right size for you.
Is there an alternative to the Mercotac Models 430, 630 and 830?
Yes. On published figures, Multi-channel Slip Ring and High & Low Temperature Slip Ring are the closest match from our supply network. An engineer confirms the fit against your application before recommending anything.
What is a split slip ring?
A split slip ring has a rotor and housing made in two halves, so it can be fitted around an existing shaft without removing the shaft or its bearings. It suits retrofits and large machines where disassembly would be costly. Expect tighter installation tolerances and possibly a lower speed rating than a one-piece unit.
What is a contactless slip ring?
A contactless slip ring transfers data, and sometimes power, across rotation without sliding contacts, using capacitive, inductive or optical coupling. There is no wear on the data path, so life is long and very high data rates are possible. Contactless power is usually limited, so many designs combine a contactless data channel with conventional power rings.
Further reading: How to select a slip ring · How to specify a slip ring · Slip rings
Other slip rings series
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