Y27 series circular electrical connector,4PIN,Y27A‑08‑04‑TJⅡ| Y27A‑08‑04‑ZKⅡB

Product Overview

The Y27 series is a family of 4 pin circular connectors for equipment that has to keep running when the panel is crowded, the cable bundle is being pulled, and the air is not clean. A cylindrical shell mates on a straight axis, so the plug and socket can be joined inside a recessed opening or a short cable run where a rectangular interface would foul the surrounding hardware. Load spreads evenly around the shell instead of concentrating on one edge, and that is why the housing rides out the small knocks and continuous vibration a machine frame passes into everything bolted to it.

In service, industrial circular connectors earn their keep at the service hatch: a technician unplugs one cable, swaps a motor or a sensor head, and plugs it back in without opening the enclosure. The Y27 range is built around that routine — a keyed shell that mates only one way, a lock you can feel at the collar, and four contacts that carry a supply pair and a control pair down a single cable run. Both variants share the same shell diameter, so they take the same panel space; what separates them is the locking method, the seal design and the current each contact will carry.

Variant Comparison

Contact System

• Gold-plated brass contacts. Plating holds contact resistance low and steady through repeated mating, so signal-level circuits do not drift and power pins do not build heat at the interface.
• Supply and control in one shell. A 4 pin circular connector can carry a two-pole supply alongside a control or feedback pair, which takes a second gland and a second panel opening out of the build.
• 250 V AC/DC working voltage. The contact set is rated for 250 V AC/DC circuits, covering the control and low-power distribution voltages found in most machine cabinets.
• Retention that survives service work. Contacts are held by the insulator rather than by the wire, so pulling a cable during maintenance does not drag a pin out of position — one of the details that separates a high reliability circular connector from a look-alike.
• Wiring that stays consistent. Pin assignment is fixed by the shell keying, so a replacement cable assembly goes back exactly the way the original came out and a mis-wired plug cannot be forced home.

Sealing Design

Sealing is the part of a connector specification that decides whether the part survives its second year. Both variants are IP67: dust-tight, and rated for immersion in water up to 1 metre for 30 minutes. That covers the ordinary accidents of plant life — a washdown hose that strays, a cabinet door left open in rain, a machine rinsed down at a sensible distance. For a waterproof circular connector, the value is less about the rating line on a sheet than about how few callouts it produces.

The ZKⅡB goes further with a double O-ring seal that keeps moisture and contaminants out under sustained exposure, which is how it reaches effective IP68-level protection in marine, mining and other wet duty. Handling matters as much as the seal itself: keep the mating faces clean and dry before closing the pair, check that the O-ring sits evenly in its groove, and cap an unmated connector in a wet area. Even high-specification sealed circular connectors fail on that one habit rather than on the design.

Environmental Suitability

• Temperature swings. The build is intended to hold its geometry through extreme temperature, from a cold start to a warm cabinet. Tell us the ambient and surface temperature your equipment actually sees and we will confirm the rated window for the variant on your order.
• Chemicals, oils and coolant. Corrosion-resistant alloys and polymer insulation are selected for exposure to chemicals, oils and moisture rather than for clean-room duty, so coolant mist and hydraulic seepage do not turn into a yearly replacement item.
• Vibration and repeated handling. Recurring vibration is what loosens ordinary connectors: the coupling backs off, the contact frets, resistance creeps up. A positive lock and keyed mating are what keep the pair together on a press, a conveyor or a vehicle-mounted skid.
• Semi-protected indoor duty. Inside a control panel, a robot cell or an indoor machine, the TJⅡ is usually the economical answer, and its push-pull action makes it quick to cycle during changeovers or fault finding.
• Outdoor, marine and wet duty. Where the cabinet sits outside, on a vessel or over a washdown drain, the ZKⅡB is the harsh environment connector of the pair, and its double seal and nickel-coated stainless housing are what justify the step up.
• Mixed sites. Plants that run indoor cabinets and outdoor skids side by side often settle on one family so that a single spares box covers both; industrial circular connectors that share a shell diameter and mating geometry make that practical.

Housing and Materials

Behind the part number sits a short list of build decisions: a corrosion-resistant alloy shell, a moulded polymer insulator, and gold plating on the contacts, assembled so the three hold their alignment over the life of the machine. That combination is what a circular connector manufacturer is really quoting when it prices a sealed four-pin part, and it is why the body resists abrasion, cleaning agents and the constant small movement of a working cable assembly.

The ZKⅡB replaces the standard housing with stainless steel under a nickel coating, which adds abrasion resistance and slows degradation where the connector is handled often or left outdoors. Over a machine's life that shows up as fewer cracked shells and fewer rejections at incoming inspection. Where a harsh environment connector is specified, check the plating against the cleaning chemicals on site: nickel stands up to most industrial washes but not to every concentrated acid, and your cleaning supplier's data sheet settles that faster than a guess.

Performance in Service

• Low insertion force, repaid in technician hours. A pair that seats by hand instead of by force protects the contacts and shortens every service visit; across a line with dozens of connections, that adds up to a maintenance budget rather than a purchase price.
• Improved EMI/RFI shielding on the ZKⅡB. The shielded build keeps electrical noise out of sensitive control circuits, which matters when a drive, a welder or a radio set shares the cabinet with the connector.
• Field-serviceable by design. The modular construction lets a damaged connector be changed at the panel without re-terminating the whole cable assembly, which is the difference between a short stop and a lost shift.
• Mating feel as a diagnostic. Each closure should end with the same firm stop. A connector that suddenly closes with no resistance is telling you the lock or the seal needs attention, and that warning is worth more than a scheduled inspection.
• Consistent from unit to unit. A fixed set of dimensions and a published standard reference mean a connector bought this year still fits the panel cut last year, so a fleet of identical machines stays serviceable without re-drilling or adapters.

Applications and Industry Benefits

The same circular electrical connector turns up across a surprising spread of equipment: assembly stations and robot cells on the plant floor, battery-management and sensor looms on rail vehicles, inverter and turbine cabinets in the energy sector, and the washdown bays of food and marine operations. What these builds share is not the industry but the constraint — a sealed, keyed connection that survives handling, cleaning and vibration, and that can be replaced from a spares shelf rather than from a specialist's bench.

For a great many of those builds, a 4 pin circular connector is the right size: two contacts for the supply and two for control, feedback or an interlock, in a shell that still passes through a cable gland and a crowded panel wall. Choosing the four-pin body over a larger arrangement keeps cable diameter and bend radius down, which is often the real limit when a machine is being tightened up rather than designed from scratch.

Industrial Automation

• Production and assembly lines. Every changeover means connectors are cycled, often by gloved hands in a hurry. A lock that seats in one movement, and a shell that carries its own keying, keeps those cycles from turning into bent pins.
• Robot cells and cable dress packs. Where the cable assembly flexes with the arm, the connection has to hold its contact pressure through constant movement; a locked pair inside a strain-relieved dress pack is what keeps a wrist axis from dropping its feedback signal.
• Conveyors and handling equipment. Motor, photo-eye and valve connections on a moving frame see vibration all day. A sealed body and a positive lock mean the connector does not need re-seating at every shift start.
• Sensor and actuator networks. A machine with dozens of sensors is only as tidy as its cabling. Standardising on one family of industrial circular connectors across sensors, actuators and junction boxes keeps the spares to a single box and makes a fault easy to trace with a meter.
• Panel building. For panel builders, a four-pole circular power connector that carries supply and control in one shell shortens the wire list and gives the enclosure door a cleaner layout, with fewer penetrations to seal.
• Retrofit and repair. When a connector fails mid-shift, the replacement must match the existing shell and pin assignment so the cable assembly goes straight back on. Photograph the marking on the old part before it comes off — that number is easier to match than a description.

Renewable Energy

Solar and storage systems put connectors where nobody visits them for years: on a tracker arm, under a combiner box, on the back of a string inverter. Thermal cycling between a hot afternoon and a cold night works at every joint on the array, and a connection that lets moisture in during that cycle becomes a service call in a place that is awkward to reach. A high reliability circular connector earns its place there by holding contact pressure and seal integrity through the cycle rather than by posting impressive numbers on a sheet.

Wind equipment is harder still. Nacelle and hub wiring sees constant low-amplitude vibration, salt air on offshore units, and maintenance access that costs far more than the part. A waterproof circular connector with a double seal and a locked coupling reduces the chance of a repeat visit, and the shielded ZKⅡB build keeps inverter and generator control signals clean where heavy electrical noise is part of the environment. Specify the variant against the enclosure rather than against the price list — the extra protection is a minor cost compared with the climb.

Mating and Installation

1. Compare the number on the part you are replacing with the number on your drawing or BOM before anything is unplugged; the series name alone does not identify a lock style or a seal grade.
2. Check that the panel opening and the cable assembly length still clear the connector body once the cable is dressed — the shell needs room to be turned, or pulled straight back.
3. Line up the keyway on the plug with the key on the socket. It engages one way only; if it does not seat with light pressure, the keying is misaligned, not tight.
4. Close a TJⅡ by pushing straight on until the pull-lock seats. Close a ZKⅡB by pushing and turning the bayonet collar until it stops and the lock engages.
5. Pull back gently on the mated pair to confirm the lock has taken. A connector that comes apart under light tension was never locked, and that is the failure most often found in the field.
6. Inspect the seal face and O-ring before closing a pair in a wet area, and wipe both dry. Grit trapped in the seal is the most common reason sealed circular connectors leak in an otherwise sound installation.
7. Support the cable behind the connector with a clamp or a tie so the seal carries no hanging load, then re-check the lock after the machine's first full operating cycle.

Ordering and Delivery

• Full series held in stock. The complete range is stocked and not every item is displayed on our website, so work from the model list when you need a particular arrangement rather than from a photograph.
• Order on the reference. A circular connector manufacturer's list and ours should line up line for line: quote the full part number from your BOM or from the old part, and the quotation, packing label and invoice all carry the same reference.
• What to send with an enquiry. Part number, quantity, destination country and the date you need the goods on site — those four details are enough for a firm quotation.
• One-stop export service. Shipments move under a one-stop export service, with export documents, marking and freight arranged through a single channel, so a distributor is not left stitching the paperwork together at the port.
• Lead time and packing. Confirm the current lead time, packing method and terms with your sales contact when you place the order; they change with quantity and destination, and we would rather quote them than have you plan around an assumption.
• Samples. If you need to check the shell and lock action on the bench first, ask your sales contact about sample availability and the terms that apply.
• Mixed orders. Orders that combine the Y27 range with other circular, rectangular or fiber-optic families can be quoted together — ask your sales contact to confirm combined packing and documentation for the shipment.

Technical Support & Model Matching

Specifying the right part is easier with an engineer on the other end of the conversation. Our technical team helps you match a requirement to the correct reference — comparing series, contact count, coupling and mounting style against the drawing or part number you already hold — and works through troubleshooting with you when a mated pair or an installed assembly does not behave as expected. We also advise on installation and commissioning practice, and coordinate sourcing, pre-shipment inspection and export documents through our supplier network, so what arrives matches what was agreed.

FAQ