How do you test this transformer with a multi-test meter? It was in a gong style door bell system. The 'clanger' unit has two windings withe the striker arm parallel to the end of the windings. Elaborate please. parts are difficult at my location.
Dude This is an AC voltage the VA is the Power or Watts Ohms law PVA Volts multiplied by the Amps. They use an elecromagnet to actvate the plunger to stike the chime bar. Edzo It should state either VDC if it is DC volts. which it is not.
Are you testing the transformer or the door bell solenoid coil? If it's the transformer: 1. ANY transformer has to be AC doesn't it? 2. 16V. x 10A. 160VA. 3. With your multi -tester set for continuity or OHMS: a. test both coils for continuity.(Low resistance) b. test both coils for non-continuity to the frame, (ground). There should be no flow, very high resistance. If it's the chime coils: Test both coils for continuity, (There will probably be a 'common' 'return' connection) and for insulation, (no continuity to ground - the frame.) If the above check out, the unit should work unless there's some mechanical damage. Look for a jammed operating rod etc.
Watts are not equal to VA. VA equals volts times amps, just as do Watts. However, Watts measures power, meaning volts and amps are in phase with each other. Doorbells are inductive, and transformers are inductive, meaning the current (amps) and the volts may not be in phase. That's why it's convenient to rate transformers in VA, because the manufacturer cannot know what load is going to be applied. Generally, watts used in a system will be less than VA, because watts equals VA times the phase angle.
Irv has an obvious error in his math. You have stated that the transformer is already marked as 10 VA that is 10 Watts regardless of voltage. With a 16V XFMR that would work out to 0.625 Amps.
Transformers output AC by nature - only those special black plastic 'wall wart' things sometimes output DC as they have rectifier in them. But a transformer out of a doorbell is just a lot of wire wound on a metal core and outputs AC. The 10VA means volt-amps - which as the other guy already said is watts. 10 watts is a really small transformer. It will not hurt your doorbell if the new transformer is rated at more than 10 watts - it just has to be the right voltage. You set your meter to AC volts and measure across the secondary winding - the output - the wires that go to the doorbell circuit - should be 16V AC. Good luck.
