Momentary Pushbuttons

Momentary pushbuttons switch their contacts only while pressed and spring back when released, for start, stop, reset and jog functions. Maple Systems PBS111 momentary pushbuttons are 22 mm panel-mount buttons, IP65 rated and cURus recognized, with flat, guard ring or mushroom heads, illuminated (24 VDC) or non-illuminated, with one or two NO or NC contacts and plastic or metal rings.

How to Choose a Momentary Pushbutton

A momentary pushbutton acts only while it is held down. If the button should stay on or off after it is released, choose a latching pushbutton; for an emergency stop, a latching E-stop; to show status without a button, an indicator light. For how momentary and latching buttons differ, read How Push Buttons Work. For a momentary button, check these six points.

Head style. A flat head is the general-purpose button for start, reset and jog. A guard ring head has a raised ring around the button so it is not pressed by accident, which suits start buttons. A 35 or 40 mm mushroom head is a large target pressed with the palm; NFPA 79 calls for an extended or mushroom head on stop buttons.
Contacts. Red buttons come with one or two normally closed (NC) contacts, for stop. Every other color comes with one or two normally open (NO) contacts, or one of each. See NO and NC Contacts.
Illuminated or not. Illuminated buttons light with a 24 VDC LED and include the lamp holder. They come with flat, guard ring and transparent mushroom heads.
Color. Green, red, yellow, blue, white or black (black is non-illuminated only). Pick the color by what the button does, as described in Momentary Pushbutton Colors.
Border and ring. Plastic or metal. On flat and guard ring heads, the metal option has a metal border and ring; on mushroom heads, the border stays plastic and only the ring is metal.
Environment, approvals and mounting. Rated IP65. CE and cURus, a UL recognized component for use in UL listed equipment. Fits a standard 22 mm hole in panels 1 to 5 mm thick.

Configure Momentary Pushbutton

Maple Systems Pushbuttons - non-illuminated, Momentary, Flat, Plastic, Black - PBS111CP22K-10 — **Flat head:** the general-purpose button.

Maple Systems Pushbuttons -illuminated, Momentary, Guard Ring, Plastic, Blue- PBS111IP22B-10L2 — **Guard ring head:** the ring helps prevent accidental presses.

Maple Systems Pushbuttons - non-illuminated, Momentary, 40mm Knurled Mushroom, Red - PBS111GP22R-01 — **Mushroom head:** a 35 or 40 mm head, pressed with the palm.

Maple Systems Control Panel Pushbutton Illuminated Knurled Mushroom Head Plastic Green 22mm PBS111KP22G-10L2 — **Transparent mushroom head:** a 40 mm mushroom that lights up.

NO and NC Contacts

A normally open (NO) contact is open at rest and closes while the button is pressed. A normally closed (NC) contact is closed at rest and opens while the button is pressed. Stop buttons use NC contacts, so a broken wire or loose terminal also stops the machine; with an NO stop button, a broken wire looks the same as a button nobody pressed. Each button ships with its contacts assembled; NO and NC contact blocks are also sold separately to add more.

Contacts	When pressed	Typical use
1 NO	Closes one circuit	Start, jog or reset; a PLC input
2 NO	Closes two separate circuits	One press sent to two circuits, such as a contactor and a PLC input
1 NO + 1 NC	Closes one circuit and opens another	Start one circuit and interrupt another with one press
1 NC	Opens one circuit	Stop
2 NC	Opens two separate circuits	Stop two circuits at once

Momentary Pushbutton Colors

A pushbutton’s color tells the operator what the button does before they press it. IEC 60204-1, the safety standard for the electrical equipment of machines, sets the colors. NFPA 79 rules out the same colors but prefers different ones, so a green start button and a red stop button meet both. Keep a red stop button away from emergency stops, and never put a red button on a yellow background, which is reserved for emergency stops. Maple Systems PBS111 pushbuttons come in green, red, yellow, blue, white and black. To see one color only, use the Lens Color filter in the products above.

Button	Colors	Never
Start or on	White, grey, black or green (IEC 60204-1 prefers white, NFPA 79 green)	Red
Stop or off	Black, grey, white or red (IEC 60204-1 prefers black, NFPA 79 red)	Green
Jog (runs only while held)	White, grey or black	Red, yellow or green
Reset	Blue, white, grey or black	Green
Abnormal condition, such as interrupting an automatic cycle	Yellow

Pushbutton Accessories and Replacement Parts

Every PBS111 ships assembled with its contacts and, on illuminated buttons, the lamp holder. To finish the panel, add legend plate frames labeled START, STOP and other functions, mount the buttons in a pushbutton control station with 1 to 5 holes, or fit a switch guard or padlock cover to prevent accidental or unauthorized presses. Extra NO and NC contact blocks and replacement LED bulbs are sold separately. These parts are listed for use with Maple Systems 22 mm pushbuttons.

View All Pushbutton Accessories

Maple Systems Pushbuttons-Accessories- NO Contact Block (Normally Open) - PB020001 — Contact Block

Maple Systems pre labeled legend plate frames - PB04002L — Legend Plate Frame

Maple Systems PB01002B, assembled double yellow pushbutton control box — Control Station

Maple Systems Pushbuttons-Accessories- Switch Guard- PB020012 — Switch Guard

Maple Systems Pushbuttons-Accessories- Padlock Button Protector- PB020010 — Padlock Cover

Maple Systems Pushbuttons-Accessories- Green Replacement LED- PB03024G — Replacement LED Bulb

Momentary Pushbutton FAQs

Should a stop button be normally open or normally closed?

Normally closed. In a standard stop circuit, a broken wire or loose terminal on an NC stop button opens the circuit and stops the machine, the same as pressing the button. On an NO stop button, the same fault goes unnoticed until someone presses stop and nothing happens. Every red Maple Systems PBS111 pushbutton comes with normally closed contacts, 1 NC or 2 NC.

What does 1 NO + 1 NC mean on a pushbutton?

The pushbutton has two separate contacts, one normally open (NO) and one normally closed (NC). Pressing the button closes the NO contact and opens the NC contact, so one press can start one circuit and interrupt another. PBS111 offers 1 NO + 1 NC in every color except red, which comes with NC contacts only.

Can a red mushroom pushbutton be used as an emergency stop?

No. An emergency stop must latch when it is pressed and stay latched until someone releases it by hand, and a momentary pushbutton springs back as soon as it is released. A red button on a yellow background is the recognized sign for an emergency stop, so do not mount a momentary mushroom button on a yellow background or under an emergency stop label. For emergency stops, use a latching E-stop.

Can I add more contacts to a momentary pushbutton?

Yes. Every PBS111 ships with one or two contacts already assembled, and normally open (PB020001) and normally closed (PB020002) contact blocks are sold separately. Contact our team to confirm how many contact blocks fit the button you choose.

Can an illuminated pushbutton switch a 120 VAC circuit?

Yes. The contacts on every PBS111, illuminated or not, are rated AC-15 for 6 A at 120 VAC and 3 A at 240 VAC, so they can switch an AC control circuit. The LED is rated 24 V, so it cannot run on 120 VAC.

Not sure which pushbutton fits your panel?

Tell us what each button needs to do and your control voltage, and our team will help you choose.

Contact Our Team