tailieunhanh - Ebook Wiring manual 2011: Part 2

(BQ) Part 2 book "Wiring manual 2011" has contents: Contactors and relays, motor-protective circuit-breakers, circuit-breakers, all about motors, export to world markets and north America; standards, formulae, tables. | Contactors and relays Eaton Wiring Manual 06/11 Page Contactor relays 5-2 Contactors DIL, overload relays Z 5-8 Contactors DIL 5-14 Overload relays Z 5-20 ZEB electronic overload relay 5-23 ZEV electronic motor-protective system 5-26 Thermistor overload relay for machine protection EMT6 5-33 CMD contactor monitoring device 5-36 5-1 5 5 Contactors and relays Contactor relays Eaton Wiring Manual 06/11 Contactor relays Contactor relays are often used in control and regulating functions. They are used in large quantities for the indirect control of motors, valves, clutches and heating equipment. In addition to the simplicity which they offer in project engineering, panel building, commissioning and maintenance, the high level of safety which they afford is a major factor in their favor. 55 Security The contactor relay contacts themselves constitute a considerable safety feature. By design and construction they ensure potential isolation between the actuating circuit and the operating circuit, in the de-energized state, between the contact input and output. All DIL contactor relays have double-break contacts. The Employers' liability insurance association demands that, for control systems of power-driven metalwork presses, the contacts of contactors must be interlocked and opposing. Interlocking means that the contacts are mechanically connected to one another such that N/C contacts and N/O contacts can never be closed simultaneously. At the same time, it is necessary to ensure that the contact gaps are at least mm over the lifespan, even when defective (. when a contact is welded). The contactor relays DILER and DILA fulfil this requirement. Contactor relays DIL Two contactor relay series are available as a modular system: • Contactor relays DILER, • Contactor relays DILA. Modular system The modular system has many advantages for the user. The system is formed around basic units, which are equipped with additional functions by means .