Ads
related to: variable speed water pump control board relayglobalindustrial.com has been visited by 100K+ users in the past month
larsonelectronics.com has been visited by 10K+ users in the past month
Search results
Results from the WOW.Com Content Network
Small variable-frequency drive Chassis of above VFD (cover removed). A variable-frequency drive (VFD, or adjustable-frequency drive, adjustable-speed drive, variable-speed drive, AC drive, micro drive, inverter drive, variable voltage variable frequency drive, or drive) is a type of AC motor drive (system incorporating a motor) that controls speed and torque by varying the frequency of the ...
Normally closed mercury relay, with coil around top of tube and adjustable angle. A mercury relay (mercury displacement relay, mercury contactor) is a relay that uses mercury as the switching element. They are used as high-current switches or contactors, where contact erosion from constant cycling would be a problem for conventional relay contacts.
Variable Speed Fire Pump Controllers were invented and released with a UL Listing for fire pump service in 2003 by Master Control Systems, Inc. [1] [2] Paragraph 10.5.5 in the 2003 edition of NFPA-20 recognized Variable Speed as an accepted method for operating the fire pump. Then in the NFPA-20 2007 edition, section 10.10 was added to clarify ...
Published in 1984 by Karl Johan Åström and Tore Hägglund, [25] the relay method temporarily operates the process using bang-bang control and measures the resultant oscillations. The output is switched (as if by a relay, hence the name) between two values of the control variable. The values must be chosen so the process will cross the ...
HVAC (Heating, Ventilation and Air Conditioning) equipment needs a control system to regulate the operation of a heating and/or air conditioning system. [1] Usually a sensing device is used to compare the actual state (e.g. temperature) with a target state. Then the control system draws a conclusion what action has to be taken (e.g. start the ...
With a variable-speed drive on the pump or fan, the supply can be adjusted to match demand and no extra loss is introduced. For example, when a fan is driven directly by a fixed-speed motor, the airflow is designed for the maximum demand of the system, and so will usually be higher than it needs to be.
Ads
related to: variable speed water pump control board relayglobalindustrial.com has been visited by 100K+ users in the past month
larsonelectronics.com has been visited by 10K+ users in the past month