Reversal Valve Problem, 1

[Fernando79]

We have a Farval greasing system to our equipment. The reversing valve is FR10 if any one knows that, and the coil resistance around 3 Ohms ,
We faced a problem that we cant put a fuse in the output of the transformer less than 10 Amps
Even though the transformer is 250VA , the problem rises when the pressure switch on all the time It burns the transformer and we will lose the coil of the valve even more all the starter fuses will blown
the Transformer voltage is 110 and if the Pressure switch has a problem and no one see that the Transformer will burnt out , any ideas what shall I do ??

F

 

[waross]

By switching time, most of us here would understand you to meen the time between the application of the current and the completion of the valve travel.
In the size of contactors normally supplied from this size transformer, a very slow contactor may have a transit time of 100 ms, or 1/10 second. Most would be considerably faster.
At 4 seconds, I suggest that you call a greasing system expert to examine your valves for mechanical or consumables problems.
Is this system being used with grease much hevier than it was designed for. Has some grease gone hard in the valves? Is the system being used at 40 deg. below, with no heating, or faulty lubrication heating?
Blown fuses may be a symptom rather than a cause. If you treat the symtoms rather than the root problem, the problem will often break out somewhere else. When it does, it is often much harder to solve. Actually, I often find that the correct solution is the simplest.
respectfully