Omron / Relays and sockets

Which socket fits which relay, the temperature derating almost nobody applies, and the model suffixes that matter.

Omron relays are consumables. They wear on operation count, they sit in every panel in the country, and they are replaced constantly. The relay is usually easy; the socket is where orders go wrong.

Socket pin count follows relay pole count

The rule is simple and it is the thing to get right.

An MY4 will not fit an 8 pin socket. If someone has changed a 2 pole relay for a 4 pole to get extra contacts, the socket has to change too.

Confirmed sockets

The PY08 is the PCB-mount version. Contact terminals sit at the top and coil terminals at the bottom. Operating range minus 25 to plus 85 degrees C.

The temperature derating nobody applies

Straight from the Omron datasheet, and it catches out hot panels.

Maximum operating ambient temperature for the PYF08A-N and PYF14A-N is 55 degrees C.

Above 40 degrees C, reduce the current to 60 percent.

So a socket rated 5 A is a 3 A socket in a panel running at 45 degrees. New Zealand plant rooms and outdoor cabinets in summer routinely exceed 40 degrees inside the enclosure.

If relays in one particular panel keep failing and the same model is fine elsewhere, panel temperature is worth measuring before blaming the relay.

The socket is often the limiting part, not the relay

Worth stating plainly because it reverses the usual assumption.

Omron states the MY2 and MY2S can be used at 70 degrees C with a carry current of 7 A.

So the assembly is limited by the socket. Fitting a better relay into the same socket changes nothing.

The same derating logic applies to power supplies in the same panel, covered on our S8 power supplies page.

Reading an MY model number

The suppression suffix protects whatever drives the coil

The -D2 and -CR suffixes are coil suppression. A relay driven directly from a PLC output should have one.

If you are replacing both a relay and an output module on the same circuit, missing suppression is very likely the reason. An unsuppressed coil generates a reverse spike on de-energising, and that spike goes into the transistor or contact that switched it.

A diode is polarity sensitive. A -D2 relay fitted the wrong way round on a DC coil shorts the supply through the diode.

That is the same argument as the contactor coil suppression on our SIRIUS and 100-C pages.

MY models

Coil voltage is a separate selection. The same model number exists in 12 V DC, 24 V DC, 110 V AC, 230 V AC and others. Tell us the coil voltage as well as the model.

Short bars are cut to length

Useful and often missed. Omron makes short bars for linking socket terminals across a row.

Omron states these can be cut to any desired length according to the number of sockets. So you buy one bar rather than a bar per group, which is cheaper and tidier than individual jumpers.

Panel mounting note

Omron specifies a panel plate thickness of 1 to 2 mm for mounting sockets. Socket insulating coatings must withstand 1500 V for one minute, in PE or PA material.

Hold-down clips are a separate part

Small, cheap and frequently missing.

A relay in a socket on a vibrating machine will work loose without one. On a conveyor drive panel or anything mounted on the machine rather than in a standalone cabinet, that is a real failure mode.

If relays in one panel keep going intermittent rather than failing outright, check whether the clips are fitted before ordering more relays.

The other relay families

G7SA is a safety part

Worth calling out. The G7SA range has forcibly guided contacts, which is what allows a safety circuit to detect a welded contact.

Forcibly guided means the normally open and normally closed contacts are mechanically linked, so they cannot both be closed at once. If one welds, the other is held open and the monitoring circuit sees it.

A standard relay is not a substitute for a G7SA in a safety circuit, however similar the contact arrangement looks. See our Omron safety page, and note the same caution about safety assessments applies.

Same principle as the 100S-C safety contactors on our Guardmaster page.

Solid state relays behave differently

Worth knowing before substituting one for a mechanical relay.

A solid state relay passes a small leakage current when off. On a high impedance load or a neon indicator, that can be enough to keep it faintly energised.

And it dissipates heat in proportion to load current, so a G3 switching a substantial load needs a heatsink that a mechanical relay does not.

On a high cycle application the solid state relay is the right answer, because a mechanical relay is a consumable there.

Socket families follow the relay

If you send us the relay we will quote the matching socket. If you only need one of the two, say so.

Before ordering more relays

What to send us

The relay model number and the coil voltage. The voltage is a separate selection.

Whether you need the socket as well.

Whether the panel runs hot, because that changes the derating.

Whether the coil is driven from a PLC output, which decides whether you want a suppression variant.

Quantities. Relays are a store item and we quote lists rather than lines.

What we can supply

Current production. The full MY, LY, G2R, G7L, G7SA, MK and G3 relay ranges, matching sockets, short bars, hold-down clips and timers. Quoted with a delivered lead time.

Bulk and consumable orders. Relays and sockets are exactly the kind of thing a maintenance store runs out of. Send us your list and we will quote the lot rather than line by line.

Discontinued variants. Older MY, LY and MK models. Surplus and tested used.

Related

Omron overview, S8 power supplies and Omron safety for G7SA and safety relays.

For interface relays and contactors from other brands see Phoenix Contact PLC-INTERFACE, Siemens SIRIUS, Allen-Bradley 100-C and Schneider Zelio relays.

Send us your model numbers

Include the coil voltage, since that is a separate selection from the model. Tell us whether you need the socket as well, and whether the panel runs hot. Quotes in NZD including GST.

Request a quote

Industech is an independent supplier of new, surplus and used industrial automation equipment. We are not an authorised distributor of, approved by, sanctioned by, or affiliated with OMRON Corporation. Omron is a trademark of OMRON Corporation. All trademarks, brand names and model numbers are the property of their respective owners and are used here for identification purposes only.