Schneider Electric 29452 Low-Level Auxiliary Contact

29452: low-level auxiliary contact for circuit breaker status signals

The 29452 is a low-level auxiliary contact for moulded-case and power circuit breakers. In the datasheet it is described as a breaker status contact with one changeover element, listed under the short names SD, SDV, OF and SDE, with local signalling of open/close, relay trip and electrical fault trip, and it clips on to the breaker. Seven Star LLC supplies the 29452 in Oman and the GCC as an independent supplier in Muscat.

The word low-level is the point of this reference. The datasheet gives a minimum load of 1 mA at 4 V DC, against 100 mA at 24 V DC for the standard contact 29450, so it is the contact that stays reliable where the signal is a few volts and a few milliamperes, for example an input to a PLC, a building management gateway or a protection relay logic input.

29452 technical specifications

Switching ratings of the 29452

The datasheet gives the conventional thermal current as 5A and lists breaking capacities by utilisation category. In category AC-12 (resistive control loads) the contact breaks 5 A at 24 V AC and 5 A at 220 to 240 V AC. In AC-15, which describes inductive loads such as contactor coils and relays, the figure falls with voltage: 3 A at 24 V, 2 A at 220 to 240 V and 1.5 A at 380 to 440 V.

On direct current the contact is rated 5 A at 24 V DC in DC-12 and 0.3 A at 250 V DC in DC-12, while in DC-14 (inductive DC loads) it is 1 A at 24 V DC and only 0.03 A at 250 V DC.

The full list is in the table below. For any real circuit, work from the voltage and the load category first and the current second, because a contact that happily switches 6 A of resistive load can fail quickly on a small inductive DC coil.

Where the 29452 fits: the breaker ranges and Galaxy compatibility

Two compatibility groups are listed. The first matches the standard accessory range: ComPact NS630b to 1600, ComPact NS1600b to 3200, ComPact ComPacT INS, ComPact Compact INV, ComPact NSX, EasyPact CVS, PowerPact Multistandard, ComPact NSX DC. The second is specific to this low-level version and lists Galaxy PX, Galaxy VL, Galaxy VM, Galaxy VS, Galaxy VX.

The datasheet also describes the part as a spare for ComPact NS630b to 1600 and for NS1600b to 3200. Always check that the accessory slot of your breaker type accepts it before ordering, because the datasheet lists four functions under one reference and the breaker documentation tells you which one a given slot reports.

Standard or low-level: choosing between 29452 and 29450

The two parts are electrically similar in rating at higher voltages, so the choice is driven by load. Use the 29452 when the contact feeds a high-impedance electronic input, because a standard contact is specified with a higher minimum load and may give unreliable readings at such tiny currents. Use 29450, with its spring terminals (Spring 0.5 to 1.5 mm² (20 AWG to 16 AWG)), when the contact drives a contactor coil, a lamp or an indicator relay at 24 V or above.

The standard contact is rated up to 6 A in AC-12 at 660 to 690 V, a voltage the low-level version does not list, so for a 690 V circuit the standard contact is the one that carries the rating.

Wiring and commissioning notes for the 29452

Wire the contact before the breaker is energised and label the function (open/close, trip or fault trip) on the terminal block, because one reference covers several functions. After wiring, operate the breaker, and trip it by a method your site procedure allows, to check that the signal reaches the PLC or alarm panel in the correct state.

Keep the signal cable away from power cables and use ferrules where the terminal design requires them. For a low level contact the practical rule is simple: stay below the category rating for your voltage, and do not ask the 29452 to carry more than its 5A thermal current.

Typical applications of the 29452 in Oman and the GCC

Breaker status contacts feed motor control centres, main and sub-distribution boards, generator and transformer incomers and the SCADA or building management systems that watch them. In oil and gas, power and water installations in Oman the 29452 is usually specified on the signal side of the board, where operators need to know if an incomer is open, closed or tripped.

In hot and dusty sites the main wear point is the clip-on connection and the wiring, so inspect it at each shutdown. Keep spares of the contacts for critical breakers, because a missing status signal can leave a control room blind to a trip.

Ordering checklist for the 29452

• Breaker or switch type and rating that will carry the contact.
• Function wanted: OF, SD, SDE or SDV.
• Load voltage and category (AC-15, DC-13 and so on) against the table above.
• Terminal type: check the wiring method in the datasheet.
• Quantity per breaker and number of breakers.
• Status: new installation or spare for an existing breaker.

RFQ details for the 29452

Send the part number 29452, the quantity, the breaker model and the control voltage, and we will confirm availability and a quotation. A photograph of the existing contact is welcome when the contact replaces one in service.

Documents and quotation

A datasheet for this product is attached on this page. It lists the ratings and dimensions summarised above and is the document to check against your drawings and load calculations.

Send us the part number, quantity and application and we will confirm availability and a quotation. Seven Star LLC is an independent supplier in Muscat and is not affiliated with the manufacturer.