Série D40Chave de nível de líquido (ponto único)

Chave de nível de ponto único que opera pelo princípio de Arquimedes — um deslocador de polipropileno não flutuante suspenso de uma cabeça de alumínio forjado muda de peso ao submergir, acionando um microswitch S.P.D.T. de 20 A (com capacidade até 500 V CA) por meio de um isolador magnético. Sem peças metálicas em contato com o líquido, carcaça IP67 completa.

Recursos

Chave S.P.D.T. de 20 A com capacidade até 500 V CA; classificação de motor UL 2 HP a 250 V CA
Sem peças metálicas em contato com líquidos
Diferencial de nível de 60 mm entre liga e desliga
Ação magnética altamente confiável
Carcaça elétrica totalmente vedada IP67
Prensa-cabo M20 integrado
Dois suportes de montagem fornecidos
Temperatura máxima do líquido de 90 °C
Cabeça elétrica de alumínio forjado maciço com deslocador e cordão de polipropileno
Tolera sólidos, lamas, polpa, espuma, escuma e detritos flutuantes

O deslocador de polipropileno não flutuante é suspenso pela parte inferior do D40 com cordão de polipropileno (3 m fornecidos de série; até 20 m disponíveis). Quando o deslocador submerge, seu peso diminui em uma quantidade igual ao peso do líquido deslocado — um ímã detecta a mudança e o braço de acionamento dispara a chave através da parede metálica sólida da carcaça elétrica. Dois suportes de montagem fornecidos (placa de montagem em parede + suporte em ângulo) para montagem direta em paredes, tampas de tanque ou vigas horizontais. Para água doce e águas residuais com SG 0,95 ou maior; não indicado para água do mar nem produtos químicos.

Mais informações

Brochura do D40
Folha de instalação do D40
Informações de recalibração do D40(versão em inglês)

Pedido — Modelos disponíveis

Modelo	Descrição
D40	D40 single-point level switch — polypropylene displacer, 3 m of polypropylene cord (up to 20 m available) and two mounting brackets supplied

Limites de operação

Fixed switching differential	60 mm
Maximum distance between D40 and displacer	20 metres (3 m of cord is supplied as standard)
Minimum distance from displacer to the floor of a tank or sump	20 mm
Minimum inside diameter of pipe housing or shroud	70 mm
Maximum liquid temperature	90 °C
Specific gravity of process liquid	0.95 or greater
Ingress protection rating (weatherproof rating)	IP56 and IP68 to 1 metre submergence

Dados elétricos

Switch type	S.P.D.T. (single pole, double throw) switch, suitable for all general control circuit applications up to 500 VAC. Ideal for the control of pump starters, relay logic circuits, and for the direct control of contactors and timers
Switch rating	Rated to 500 VAC: 20 A resistive (15 A at 500 VAC)
Motor load rating	Motor load ratings 12.5 A at 125 VAC, 8.3 A at 250 VAC and 2 A at 500 VAC (UL: 1 HP at 125 VAC, 2 HP at 250 VAC)
Maximum switched voltage	500 VAC
Maximum switched current	20 A (15 A at 500 VAC)
Resistive load rating (NC and NO)	20 A at 125 VAC; 20 A at 250 VAC; 15 A at 500 VAC; 20 A at 8 VDC; 20 A at 14 VDC; 6 A at 30 VDC; 0.5 A at 125 VDC; 0.25 A at 250 VDC
Lamp load rating	7.5 A at 125 VAC; 7.5 A at 250 VAC; 4 A at 500 VAC; at 8 VDC, 14 VDC and 30 VDC: 3 A NC / 1.5 A NO; at 125 VDC: 0.5 A NC / 0.5 A NO; at 250 VDC: 0.25 A NC / 0.25 A NO
Inductive load rating (NC and NO)	20 A at 125 VAC; 20 A at 250 VAC; 10 A at 500 VAC; 20 A at 8 VDC; 15 A at 14 VDC; 5 A at 30 VDC; 0.05 A at 125 VDC; 0.03 A at 250 VDC
Motor load rating (NC and NO)	12.5 A at 125 VAC; 8.3 A at 250 VAC; 2 A at 500 VAC; 12.5 A at 8 VDC; 12.5 A at 14 VDC; 5 A at 30 VDC; 0.05 A at 125 VDC; 0.03 A at 250 VDC
Contact loading note	Do not apply maximum voltage at maximum current across the switch contacts. See the load ratings above for current limits at specific voltages and for specific loads
Terminal identification	COM 1 (common), NC 2 (normally closed), NO 3 (normally open)
Cable gland	M20 cable gland; cable 10 mm dia. maximum; two cable crimps supplied to suit various cable sizes
Earthing	M4 earth screw provided inside the lid

Dimensões

Typical Applications

Confined locations in sumps and pits; bund-area warning alarms; cooling-tower water-level control; effluent and high-solids uses; fresh water and waste water (not for sea water or chemicals); level monitoring in wells and bores.

SG Sensitivity

Designed for liquids with specific gravity 0.95 or greater (water, water-based effluent, slurries). Because it is the change of weight sensed by the displacer as it submerges that actuates the switch, the specific gravity of the liquid directly affects operation. The D40 will only operate in liquids with an SG of 0.95 or greater; it will not operate in liquids with an SG below 0.95.

Installation and Mounting

A flat mounting plate is supplied for installing the switch against the walls of pits or tanks, plus an angle bracket for mounting on any flat horizontal surface such as tank lids or horizontal bracing. M5 threaded mounting holes in the sides of the switch body let the cable entry point to the right or left. Whichever bracket is used, the top face of the lid must be perfectly horizontal (in both planes) so the cord and displacer hang vertically beneath the switch. The slotted angle bracket suits sloping beams and tank lids and can be inverted if required; fully tighten the 2 × M5 Phillips head screws. Thread the cord through the hole at the end of the actuating arm and tie a double knot in it, then tie the free end through the hole in the top of the displacer.

Operating Environment

Detects liquid level in wells, tanks, pits, sumps, bores and bund areas. It is designed for fresh water and waste water and is not suitable for sea water or chemical solutions. Highly tolerant of liquids containing solids, slurries or pulp, and works reliably in froth or foam and where floating scum or debris is present. A solid metal wall separates the electrical enclosure from the actuating arm, so the housing is totally sealed and weatherproof provided the lid is fully tightened and the cable gland is properly used. The polypropylene cord and displacer are the only parts in contact with the process liquid.

Warm Liquids

Ideal for warm liquid applications (maximum liquid temperature 90 °C) provided the electrical head is mounted well above the liquid and is protected from hot vapour. The wetted cord and displacer are highly tolerant of liquids at elevated temperatures.

Wiring and Earthing

The D40 is a mains voltage device: all electrical work must be performed by a fully qualified and licensed electrician. To switch ON when a rising water level covers the displacer, use terminals 1 (COM) and 3 (NO). To switch ON when a falling water level uncovers the displacer, use terminals 1 (COM) and 2 (NC). Crimp one of the two supplied cable crimps onto the cable's outer sheathing at least 5 mm back from its end, pull it hard against the inner wall of the M20 gland, then fully tighten the gland (cable 10 mm dia. maximum). An M4 earth screw is provided inside the lid and all applications should be properly earthed.

Calibration

Each D40 is factory calibrated to operate with the displacer supplied. If required, re-calibrate using the M3 Allen head stainless grub screw (secured with a lock nut) on the top deck of the switch. Switching must occur within the length of the single displacer: correctly adjusted, the switch changes state at the bottom edge of the conical section on a rising level and at the seam line halfway down the straight section on a falling level. If a rising level fails to actuate the switch with the displacer fully submerged, turn the calibration screw clockwise in ¼ turn steps until it operates at the correct point. If it fails to operate on a falling level, turn the screw anti-clockwise ¼ turn and retest, repeating if required.

Hazardous Areas

The D40 is not certified for use in hazardous areas and must not be installed in any area classified as hazardous under AS/NZS 60079.10 (Zone 0, 1, 2, 20, 21 or 22).