Another solenoid question, If I have 110Vac solenoid value can I power it from 115Vac transformer and can I keep it energized for a reasonable amount of time say a few hours or will it get too hot and the coil burn out
Solenoids are rated for an inrush current for when the core is out, I would think that the designer reckoned that the core would "clunk" in in a matter of a few 100 milliseconds. Then the magnetic path is completed and the current will fall dramatically to say 15% of the core out current. So I would say that a 5% voltage overload with the core IN is OK, but 100% operating voltage with the core out is not OK.
Frank
A typical solenoid requires 10% of the normal current to remain energized. To accomplish this, use one of the following:
Mechanical hold in resistor
Capacitor discharge and hold in resistor
Transistorized hold in circuit
Pulse-width modulation
Pick and Hold
Dual voltage
Multiple coils
also choose Attribute
Quiet
Long Life
Miniature
Battery Operated
High Speed
Acceptable voltage ratings are usually +/- 10% of nominal. So 115Vac on a 110Vac solenoid is just fine.
Having said this.....
There are continuous duty and intermittent duty solenoids.
Given the same solenoid size, an intermittent duty has significantly greater pulling power than a continuous duty. But it will burn out if not allowed to rest and cool off.