Schneider Electric ZB5AS844 Red 40 mm E-Stop Head, Turn Reset

ZB5AS844: red 40 mm emergency stop head, turn-to-release

The ZB5AS844 is a Schneider Electric Harmony XB5 emergency stop head for a 22 mm panel hole, with a red 40 mm mushroom cap that latches when pressed and releases by turn to release. Seven Star LLC supplies the ZB5AS844 in Oman and the GCC as an independent supplier based in Muscat, usually to panel builders and maintenance buyers completing machine and plant stations.

The datasheet lists it as a head and basic element, so the contact blocks that actually open the safety circuit are chosen separately. The datasheet title reads “Emergency stop head, switching off, plastic, red mushroom Ø40, Ø22, trigger and latching turn to release”.

Emergency stop heads compared with ZB5AS844

These emergency stop heads share the 22 mm fixing and differ by cap size, reset action and illumination.

Panel cut-out and anti-rotation for ZB5AS844 and sealing

The datasheet specifies the panel hole as 22.5 mm recommended, with a finished-hole tolerance written as 22.3 mm plus 0.4 mm. For connection by screw clamp terminals or plug-in connectors it asks for a fixing centre of at least 40 × 30 mm, for Faston connectors 45 × 32 mm and for printed-circuit-board connection 30 × 30 mm. For this kind of operator the datasheet recommends the anti-rotation plate ZB5AZ902, which fits in the lug recess of the hole so the head cannot turn when it is operated.

The head weighs 0.046 kg and is 57 mm deep before blocks are added. Emergency stop stations are usually mounted on a yellow legend plate, which should be fitted before the head is tightened.

The datasheet lists protection of IP66, IP67, IP69, IP69K, an impact rating of IK03, and UL type 4X/13 enclosure use. The datasheet also quotes resistance to a high-pressure washer of 7000000 Pa at 55 °C from a distance of 0.1 m.

Approvals listed are CSA, DNV, BV, LROS (Lloyd’s Register), UL listed. Use the ZB5AS844 in a safety circuit only after checking the datasheet approvals and your own risk assessment; a head alone does not make a safety function.

Installation, testing and maintenance

Mount the head in a clean hole, tighten the collar evenly, and add the contact blocks before connecting the circuit. Test the latch by pressing the ZB5AS844 and checking the NC contacts open, then reset it by turn to release and check the circuit can be restored only by that action. Include the stop in routine proof tests and replace any head with cracked cap or damaged latch.

Selection checklist and RFQ information for ZB5AS844

Send the points below so that the part number can be confirmed against the datasheet and checked for availability in one reply.

• Part number ZB5AS844 and the required quantity.
• Cap diameter and reset action you need, checked against the datasheet.
• The contact blocks you plan to fit, including the number of NC contacts.
• Legend plate or yellow collar requirements, if any.
• Panel thickness and anti-rotation arrangement.
• Any approval needed by the project, compared with the datasheet list.
• Delivery location in Oman or the GCC and the lead time you need.

Typical uses in Oman and the GCC

Emergency stop heads are found on motor control stations, pump houses, compressor skids, conveyors and packaged machines across oil and gas, petrochemical, power and desalination sites. The this unit suits panels exposed to heat, dust and wash-down, because the datasheet gives sealing, temperature and shock ratings for it.

Technical specifications of the ZB5AS844

Latching action and contact blocks for this unit

The operator type is trigger action and mechanical latching. The reset is turn to release and the stated mechanical durability is 300000 cycles, a lower figure than a push-button because the latching mechanism is built for rare but critical use. The electrical composition codes listed are C7, C8, C11, C15, SF1, SR1, C10, which describe how many contact blocks can be stacked behind the head in front or rear mounting.

The standards listed include IEC 60947-5-5 and ISO 13850 for emergency stop devices, and IEC 60204-1 for machine electrical equipment where they appear in the datasheet for this reference. Check the contact blocks you pair with the head for positive-opening NC contacts in your design.

Cap size, reset action and duty of ZB5AS844

The 40 mm red mushroom is the larger of the two turn-to-release heads in this lane. It is easier to hit in a hurry, and the larger cap carries the manufacturer name and rotation arrow in the product photo.

Typical use is an emergency stop on main control desks, motor control centres and machine fronts where visibility and a large strike area are valued.

Documents and quotation

The Schneider Electric datasheet for the ZB5AS844 is attached on this page for your technical file. It holds the data summarised above together with panel cut-out and dimension drawings.

To request a quotation, send the part number and quantity through the enquiry form and we will reply with availability and delivery terms. Seven Star LLC is an independent supplier and does not act for the manufacturer, so please check the datasheet against your project requirements before ordering.