A Guide to Auto-Transformer selection

Step Down Range

The suffix "VA" can in most instances be considered to be watts* (ignoring the effect of phase angle, power factor and frequency), i.e. 200W = 200VA.

If an inadequately rated device is used, the transformer will cut out periodically or repeatedly blow fuses. In all cases it is important that the Transformer is rated ABOVE the appliance with which it is to be used.

N.B. The current drawn by an appliance at 120V will be double that drawn at 230V. 

Listed below are typical ratings: Step down: (check individual rating labels or instructions wherever possible)

Electric razors [0.05A x 120V = 6VA] Use 30VA Transformer. 
Radios [0.1 A x 120V = 12VA] Use 30VA Transformer. 
C.D. Players [0.15A x 120V = 18VA] Use 30VA Transformer. 
Christmas tree lights [0.2 A x 120V = 24VA] Use 30VA Transformer. 
Epilator [0.3A x 120V = 36VA] Use 50VA Transformer. 

Games console [0.35A x 120V = 42VA] Use 50VA Transformer. 
Heat lamps [0.45A x 120V = 54VA] Use 50VA Transformer. 

Nebulisers [0.8A x 120V = 96VA] Use 100VA Transformer. 
Televisions. [Varies - see Rating panel] Typically 50 - 300VA 
Hi-Fi [Varies - see Rating panel] Typically 100 - 300VA 
Curling tongs [1.6 A x 120V = 192VA] Use 200VA Transformer. 
Computers [1.66A x 120V = 199VA] Use 300VA Transformer. 
Travel irons [4.16A x 120V = 499VA] Use 500VA Transformer 
Electric kettles [8.4A x 120V = 1010VA] Use 1.5KVA Transformer 
Hairdryers [14A x 120V = 1680VA] Use 2KVA Transformer 
The above figures are only an indication of typical power requirements

Step Up Range

The suffix "VA" can in most instances be considered to be watts* (ignoring the effect of phase angle, power factor and frequency), i.e. 200W = 200VA.

If an inadequately rated device is used, the transformer will cut out periodically or repeatedly blow fuses. In all cases it is important that the Transformer is rated ABOVE the appliance with which it is to be used.

N.B. The current drawn by an appliance at 230V will be half that drawn at 120V. 

Listed below are typical ratings: Step *up: (check individual rating labels or instructions wherever possible)

Electric razors [0.03A x 230V = 6VA] Use 100VA Transformer. 
Radios [0.5A x 230V = 12VA] Use 100VA Transformer. 
C.D. Players [0.08A x 230V = 18VA] Use 100VA Transformer. 
Christmas tree lights [0.1A x 230V = 24VA] Use 100VA Transformer. 

Epilator [0.16A x 230V = 36VA] Use 100VA Transformer. 
Games console [0.2A x 230V = 42VA] Use 100VA Transformer. 

Heat lamp [0.3A x 230V = 54VA] Use 100VA Transformer. 
Nebulisers [0.4A x 230V = 96VA] Use 100VA Transformer. 
Televisions. [Varies - see Rating panel] Typically 50 - 300VA 
Hi-Fi [Varies - see Rating panel] Typically 100 - 300VA 
Curling tongs [0.8A x 230V = 192VA] Use 200VA Transformer. 
Computers [0.85A x 230V = 200VA] Use 300VA Transformer. 
The above figures are only an indication of typical power requirements

N.B.

(1) - This reference materiel is given on the understanding that any legal responsibility or liability for the accuracy or otherwise of any statement herein is hereby excluded in respect of the Author of the material, the Publishers of the material and the recipient of it.

(2) - Twin socket Transformers
The total load of both appliances plugged into a twin socket transformer must not exceed the rating shown on the label / catalogue.