The Auspicious A16LMSS4R is a 16mm Emergency Stop switch built for machine safety circuits that need both breaking and signalling contacts from a single device. Press the head and it latches down, holding the safety contacts open until an operator deliberately twists it to release. That latching action is what makes it a true emergency stop rather than an ordinary stop button, since the machine cannot restart the instant the operator lets go.

The four contact arrangement is what sets this model apart. Two normally closed pairs handle the safety function and can be wired as dual channels into a safety relay, while the two normally open pairs are free for signalling duty. That lets you drive a warning lamp, feed a PLC input for fault logging or trigger an audible alarm at the same moment the machine stops, without adding a second device or an auxiliary block.

The 16mm mounting diameter suits compact panels, handheld pendant stations and small machine consoles where a 22mm head would not fit. IP65 protection keeps dust and washdown water out of the front face, so it holds up in workshop and food processing environments. UL, TUV, CE and CSA approvals cover it for export machinery and inspected installations.

Key Features

Four contacts in one device with 2NC for safety and 2NO for signalling
Latching operator holds the circuit open until deliberately released
Twist to release reset prevents accidental restart
Dual channel wiring capability from the two NC pairs
Compact 16mm mounting diameter for tight panels and pendants
IP65 protection against dust and low pressure water jets
UL Listed, TUV, CE Mark and CSA certified
Light 0.025kg body suited to handheld stations

Technical Specifications

Specification	Detail
Product Type	Emergency Stop Switch
Range of Product	A16LMS Series
Model	A16LMSS4R
Mounting Diameter	16mm
Head Shape	Round
Type of Operator	Latching
Reset Method	Turn to Release
Contact Composition	2 NC and 2 NO
Degree of Protection	IP65
Illumination	Non Illuminated
Certification	UL Listed, TUV, CE Mark, CSA
Brand	Auspicious
Country of Origin	Taiwan
Weight	0.025kg
SKU	A16LMSS4R

Common Applications

Machine control panels and operator consoles, handheld pendant stations for hoists and cranes, conveyor and packaging line stop stations with status signalling, CNC and workshop machinery, food processing equipment subject to washdown, laboratory and test rigs, and any station where stopping the machine must also raise an alarm or log a fault to the PLC.

Related Emergency Stop and Control Options

Contact count is what usually decides between models in this series. If your circuit only needs the safety break and no signalling, the 16mm emergency stop button with 2NC contacts A16LMS3R2N is the simpler and slightly cheaper option, sharing the same cutout, head and IP rating.

For the full range of heads, contact blocks and larger 22mm bodies, see the emergency stop collection. An emergency stop rarely goes in alone, so browse the push buttons and emergency stop range for matching start, stop and reset operators, and the push buttons and indicators category for the pilot lamps those NO contacts can drive.

Where the stop station sits on a handheld unit rather than a panel door, the pendant station and control box range covers enclosures sized for these 16mm operators.

Why Buy From Qahraba

Qahraba supplies electrical contractors, panel builders and procurement engineers across the UAE and worldwide. Every Emergency Stop switch we stock is genuine Auspicious product with full certification. Local UAE orders ship within 1 to 2 working days, free above AED 250, or collect free from our Dubai store. Call or WhatsApp +971 52 913 9543 for bulk pricing.

FAQ

What is an Emergency Stop switch?

It is a manually operated safety device that breaks a machine control circuit immediately when pressed. The head latches in the pressed position so power cannot return until someone deliberately resets it.

What does 2NC plus 2NO mean?

The switch carries two normally closed contact pairs and two normally open pairs. The NC pairs open when the button is pressed and handle the safety break, while the NO pairs close and can drive lamps, alarms or a PLC input.

Do I need all four contacts?

Not always. Two NC contacts cover a standard dual channel safety circuit. The NO pairs are useful when you also want visual or audible indication that the emergency stop has been operated.

How is this Emergency Stop reset?

Twist the red head clockwise until it pops back out, which returns the contacts to their normal state.

Why do safety circuits use normally closed contacts?

So a broken wire or loose terminal produces the same result as pressing the button. The circuit fails safe rather than failing silently.

What panel cutout does it need?

A 16mm diameter hole. This is smaller than the common 22mm standard, so check the existing panel before ordering.

16mm Emergency Stop Switch Latching Twist to Release 2NC 2NO IP65 A16LMSS4R Auspicious