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Solenoids
- Thread starter majuba
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OperaHouse
Electrical
For the same voltage, AC coils have a much lower resistance than DC coils. AC coils use inductance of the coil to limit current. AC coils have a high inrush current until the core pulls in.
hillwilliam
Electrical
Be very careful when replacing coils used in solenoids. The ac versions generally operate at 12, 24, 120, or x120 volts ac. DC coils generally are rated at 6, 12, 100 vdc, etc.
The coil does not know if the applied voltage is ac or dc. Within limits they only care about the magnitude of the input voltage.
A coil designed for 12 vac will operate hotter (and fail quicker) when operated at 12 vdc. A coil operated at 50 Hz will also run hotter that one operated at 60 Hz. The 50 Hz is "closer" to "DC".
The force of the coil is primarily determined by NI. In an ac version the NI's are rapidly changing, thus chatter.
True there will be a surge current, approx 1.5x steady-state, in ac applications but this only occurs for approx 8-10 ms. There must be a low output impedance to the power source to allow pull-in.
The steady-state current (or DC level) provides the heating.
The coil does not know if the applied voltage is ac or dc. Within limits they only care about the magnitude of the input voltage.
A coil designed for 12 vac will operate hotter (and fail quicker) when operated at 12 vdc. A coil operated at 50 Hz will also run hotter that one operated at 60 Hz. The 50 Hz is "closer" to "DC".
The force of the coil is primarily determined by NI. In an ac version the NI's are rapidly changing, thus chatter.
True there will be a surge current, approx 1.5x steady-state, in ac applications but this only occurs for approx 8-10 ms. There must be a low output impedance to the power source to allow pull-in.
The steady-state current (or DC level) provides the heating.
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