Schneider Electric XB4BG21 Key Switch 2-Pos Stay Put 1 NO

XB4BG21 two-position stay-put key switch

The XB4BG21 is a chromium-plated metal key selector from the Schneider Electric Harmony XB4 range for 22 mm panel holes. It offers two stay-put positions at 90° and one normally open contact. Key number 455 is listed on the datasheet. Seven Star LLC supplies the XB4BG21 in Oman and the GCC as an independent supplier based in Muscat.

The datasheet describes the product as a complete unit, so the operator and the contact block come together, ready to fit into a panel door or console. The information below is taken from that document and shows where this reference sits among the neighbouring key selectors.

XB4BG21 technical specifications

How the XB4BG21 operates

This unit turns through 90° between two positions and stays where it is put. The key is withdrawn in the left-hand position, so a locked panel can be left in one defined state. With key number 455 it matches the other 455 key selectors in this group, so a single key can serve several panels if that suits your site rules. Operating torque is 0.14 N.m NO changing electrical state.

Contacts and electrical ratings of the XB4BG21

The contact block of this unit is a slow-break design with silver alloy (Ag/Ni) contacts. The datasheet gives a conventional thermal current of 10 A, a rated insulation voltage of 600 V (pollution degree 3) and a rated impulse withstand of 6 kV. Short-circuit protection is a 10 A gG cartridge fuse. Rated operational currents are listed below, and they are the figures to use for relay coils, contactor coils and PLC inputs on the control circuit.

• 3 A at 240 V, AC-15, A600
• 6 A at 120 V, AC-15, A600
• 0.1 A at 600 V, DC-13, Q600
• 0.27 A at 250 V, DC-13, Q600
• 0.55 A at 125 V, DC-13, Q600
• 1.2 A at 600 V, AC-15, A600

Sealing and environment of the XB4BG21

For operation the datasheet gives an ambient range of -40–70 °C. The degree of protection is IP66, IP69, IP69K, IP67. Impact protection is IK06 with keyhole cover ZBGP. Vibration resistance is 5 gn (f= 2–500 Hz). For shock the datasheet quotes 30 gn (duration = 18 ms) for half sine wave acceleration and 50 gn (duration = 11 ms) for half sine wave acceleration. The keyhole cover ZBGP is referred to in the datasheet for the IK06 value, and it is worth fitting where the front face is exposed to knocks or washdown.

The certifications named on the datasheet include BV, DNV and LROS (Lloyd’s Register) as well as UL and CSA, which is why this style of operator is often chosen for skids and marine-type packages. Always check the approval you need against the exact ordering reference.

XB4BG21 compared with other key selectors

The four key selectors in this group differ in the number of positions, the return action, the contacts and the approvals, as the comparison below shows.

Selection and installation of the XB4BG21

• Positions: 2 positions 90°, stay put.
• Contacts: 1 NO (terminal marking (13-14)NO).
• Key: number 455, withdrawn at the left-hand position.
• Panel: 22.5 mm mounting hole in the datasheet standard version.
• Environment: matches the temperature range and sealing listed above.
• Add a keyhole cover where impact or washdown applies.

Fit this unit through a 22.5 mm hole and tighten the fixing as the datasheet specifies: 0.8–1.2 N.m. Terminals accept ≤ 2 × 1.5 mm² with cable end and ≥ 1 × 0.22 mm² without cable end, and screw heads take Philips no 1, pozidriv no 1 or flat 4 and 5.5 mm drivers. Wire the contact to the panel with the terminal marking in mind.

At commissioning, test every key position with the control circuit energised, confirm that the key can only be withdrawn at the stated position, and record who holds the keys. Re-test the contact function after any rewiring.

Where the XB4BG21 is used in Oman and the GCC

Typical uses are local/remote or auto/manual selection on motor control panels, maintenance lock-out in pump stations, and permission switches on desalination, power and oil and gas skids. In coastal sites with salt and humidity, the IP66 to IP69K sealing is the reason this metal operator is chosen over a plastic one.

Key-controlled selectors only add safety if the key is controlled. Keep a register of who holds the keys, avoid leaving a key in the switch, and keep a spare in the maintenance office. For panels that are handed over to an operator, state in the handover documents which position is the safe state and where the key may be removed.

Information to send with an RFQ for the XB4BG21

Send the part number XB4BG21, the quantity and the delivery location in Oman or the GCC. State the number of positions, stay-put or spring return, the contacts required and whether an ATEX approval is needed. If you are replacing an installed unit, a photo of its side label or of the rear of the block helps us confirm that the reference is identical.

Documents and quotation

The official Schneider Electric datasheet for this unit is attached on this page, so each figure above can be checked against the source document.

To request a quotation, send the part number XB4BG21, the quantity and the delivery location through the RFQ form. Seven Star LLC replies with availability and lead time.