Solenoid Plug In to Higher Voltage

Yes it will smoke the coil and yes there is a load on solenoid...it's called the holding current...

http://www.industrial-electronics.com/output_devices_amplifiers_valves_relays_variable-frequency_drives_stepper_motors_servomotors/Typical_Voltages_Wattages_Solenoid_Valves.html

Why are transformers not toasted?

What is the worst subjecting the solenoid to higher voltage(220 Vac) than rated or plugging it to 55Vac low voltage supply?

Because a solenoid is a load. For linear devices, when you double the voltage, you quadruple the power dissipated.

A transformer is not designed to be a load. It is an impedance matching device for a range of frequencies. Although some will say that it is used to step-up or step-down voltages with a corresponding inverse relationship of the current, where isolation may be provided between the primary and secondary windings although certain transformers that is not automatically the case.

Oh, anything in the range between a loud buzzing sound and spontaneous and spectacular self-decomposition, which makes it a Silly Thing To Do.

AC verus DC
Just try it and report!

Have fun!

<...what will happen...?...> The act might attract a range of outcomes between minor re-training and dismissal for incompetence. It might also attract a measure of unpopularity with the facility's fire insurance company.

It's just a scenario on site. Management has issues with personnel. It can't be perfectly eliminated that some of those technicians who has grief on the management will tend to do scenes like these. Some sort of destructive testing, I presume.

It sounds like personnel has issues with management, not the other way round.

This is NOT an engineering problem.

Go to a human relations forum and air your grievances there.

Oh Lyn, I am at the management side. Exploring possibilities is an engineering endeavour prior to failure. It's what you always did in NASA, isn't it?

At the very least, you'll let the smoke out.

Who says a transformer would NOT be "toasted" by applying the incorrect voltage?

And... transformers are not used for DC, so one would never see a "110VDC transformer".

Side note: "... spectacular self-decomposition..." I like it!

1. A 110VDC solenoid (or its circuit) is likely to have a suppression diode or voltage dependent resistor wired internally or externally for spark/spike suppression. Connecting 220 VAC will blow diode/VDR and or/ fuse.
2. To get the maximum pull from the smallest assembly, the DC solenoid will saturate the iron in the magnetic circuit. Thus current much above the rated DC current will certainly get saturation with the with the equivalent AC heating current (root mean square or r.m.s. - rms = 1.11 x DC for resistive circuit) which has a peak current 1.414 x rms, even if the current were sinusoidal.
3. A pure DC solenoid will not have a laminated iron core so iron losses on AC at rated current would add to the coil DC losses. However, AC solenoids being far more common than DC, DC solenoids are often AC ones with a different winding or a resistance switched-in, once closed, to provide a "holding" current which will not overheat the coil.
4. To add to trouble, you want to apply 220VAC, potentially 220/120 (note point 2 above, 110 x 1.1 = 120 approx.) times current or 3.4 times watts, neglecting inductance. Excessive current could cause winding failure.
5. At rated coil current and 220VAC applied, a vector triangle indicates that inductive voltage drop would need to be 185 volts, a power factor of 120/220 = 0.55. Thus it could be quantified, that if current draw at 220VAC was no more than 1.1 x DC rated current and power factor <0.55, then watts loss would be no more than rating.
6. On AC, a DC coil would have fluctuating pull at 100/120Hz, which could cause "chattering" and cause damage if energised for too long.
7. It has not been specified if you have DC solenoids of one or a few types - in that case you could test with a variac to see at what AC voltage "true rms" current draw becomes excessive.