POWER FOR SOLENOID VALVE

Solenoids are inductors. There is a holding current (power) and inrush current.

The power supply needs to match the required voltage of the solenoid, provide the holding current, and also stay reasonably stiff to maintain voltage during short inrush current.

It depends on the solenoid inrush current whether the 36w power source has enough power to survive turning on. A capacitor across the power supply can help provide extra energy during the inrush when the solenoid is turned on.

Holding current is actually higher than initial current for a solenoid, since the solenoid appears like an inductor. It's not the same as (say) a DC motor, which will have a higher initial (inrush) current (unless it's stalled).

Inrush current can be three to 10 times higher than holding current and can cause extreme overheating conditions, resulting in coil burnout if it is prolonged. Source: MRO

www.mromagazine.com/.../

www.mromagazine.com/.../

Not true if DC is applied.

In fact, not _always_ true for AC either; it depends on the AC frequency. Also, did you actually read your linked article? 

This makes no sense:

"resulting in coil burnout if it is prolonged" - that's no longer "inrush" when it's prolonged. 

The article is a bit misleading since it refers to inrush current when it means current when the solenoid armature is extended out of the coil. It may common to describe it this way but it's not that helpful.

However, it is true that an AC solenoid designed for a fast pull in may well draw a lot of current if mechanically constrained in some way.

Since the OP doesn't say if he is using AC or DC we are all a bit in the dark.

SO, as usual, more info needed please.

Afiq - pictures of the solenoid and the power supply, ideally showing the ratings label, would help !

MK

Agree, hard to see how that condition could be defined as inrush, (e.g. it would be called a stalled condition for a DC motor, don't know what one would call it for an AC solenoid!). Also reminds me of an old discussion (with a blog from John Wiltrout from memory) where it was discovered that impedance could be lowered in some conditions (depending on the particular metal, and the AC frequency). Granted it's more likely to be 50/60Hz here.