What does a definite purpose contactor do?
Definite purpose contactors and starters are electrically operated switching devices specifically designed for the heating, ventilation, air conditioning and refrigeration (HVAC) industry. They are subjected to stringent quality assurance inspections and testing procedures.
What is a definite purpose magnetic contactor?
Definite-purpose magnetic contactors are designed to control electric loads found in HVAC, data processing and food service applications. They are ideal for use in commercial applications up to 90A.
Who makes Furnas contactors?
Siemens
State Motor & Control Solutions has been a premier Siemens Controls and Automation partner for over 25 years.
Are definite purpose contactors normally open or closed?
All of the C25 definite purpose contactors have normally open power poles – they do not come in normally closed power poles. We do have the C30CNE lighting contactor which is rated 30amps per pole and can have normally open OR normally closed power poles. It can be used on non-lighting applications.
What is the difference between a definite purpose contactor and a general purpose contactor?
Unlike General purpose contactors, which are rated typically based on HorsePower (HP) of the motor, Definite Purpose contactors are rated on Motor Full Load Amps (FLA). DP contactors often have limitations on the maximum Locked Rotor Amps (LRA) it can handle.
What causes contactor failure?
By far the most common cause of contactor coil failure is, surprisingly to many, undervoltage. There may be sufficient voltage to pull the contactor in, but not enough to keep the coil armature formers firmly “sealed”.
Are contactors normally open or closed?
Control Relays can and often are both Normally Open and/or Normally Closed depending on the desired function. Contactors, on the other hand, are almost exclusively designed to operate with normally open (Form A) contacts.
What is a definite purpose contactor?
Let’s start at the beginning. What are definite purpose contactors? DP contactors are electronically controlled switches that are used for switching a power circuit. Originally designed for the HVACR industry, their use has expanded to a variety of other market segments.
What are the features of a DP 45 contactor?
Siemens DP Class 45 Contactors have the advanced features that are standard across the family. These advanced features include the compact sizing, quiet operation, an encapsulated body and coil, visual contact position indication, weld-resistant silver cadmium oxide contacts, Class F coil insulation and quick connect power terminations.
What are the components of a contactor?
A contactor has three components. The contacts are the current carrying part of the contactor. This includes power contacts, auxiliary contacts, and contact springs. The electromagnet (or “coil”) provides the driving force to close the contacts. The enclosure is a frame housing the contact and the electromagnet.
What is an air conditioning contactor?
These air conditioning units carry ratings from a few tons to 500 tons. These are often used to control electric motors, lighting, compressors, elevators, pumps and cranes to pools, vending machines and food processing. A contactor has three components. The contacts are the current carrying part of the contactor.