Installing & Working with Multi-Tap Transformers

How to use the a Multi-Tap Transformer

  • Connect one wire to the 12V tap at the transformer; connect the other wire to the white (common) tap.
  • Measure the voltage at the first light using a digital voltmeter.
    • Example: 10V
  • Subtract the measured voltage from 12. This equals your voltage drop.
    • Example: 12-10V = 2V
  • Add the voltage drop to 12. This is equivalent to the voltage tap you should use.
    • Example: 12V + 2V = 14V
  • Move the wire from the 12V tap to the calculated voltage tap.
  • Leave the other wire connected to the white (common) tap.
    • Example 14V – The 14V tap on the transformer is Red.
  • Add additional lights observing the “Low Voltage Layout Rules” outlined in the Layout subcategory.
  • Below is a cheat sheet chart to use if a volt meter is not available for 12 gauge wire. Remember, its only the distance to the first fixture that matters. This chart is true if and only if you use the “T” method outlined in the Layout subcategory, or if use the “Daisy Chain” method with no more than 2 fixtures. Note – the colors on the chart correspond to the colored wires on the Unique transformer. The FX transformer does not use colors.

Voltage Tap Chart for #12-2 Wire

Watts
20
40
60
80
100
120
140
160
180
Distance to 1st Fixture
Voltage Tap to Use on Transformer
25′
12
12
12
13
13
13
13
13
13
50′
12
13
13
13
13
14
14
14
14
75′
12
13
13
14
14
14
15
15
16
100′
13
13
14
14
15
15
16
16
16
125′
13
13
14
15
15
16
16
16
18
150′
13
14
14
15
16
16
18
18
18
175′
13
14
15
16
16
18
18
20
20
200′
13
14
15
16
16
18
20
20
22
225′
13
14
16
16
18
18
20
22
250′
13
15
16
16
18
20
20
275′
13
15
16
18
18
20
22
300′
14
15
16
18
20
325′
14
16
16
18
20
350′
14
16
18
20
20
375′
14
16
18
20
22
400′
14
16
18
20
425′
14
16
18
20
450′
14
16
18
22
475′
15
16
20
22
500′
15
16
20
525′
15
18
20
550′
15
18
20
575′
15
18
20
600′
15
18
22
625′
16
18
22
650′
16
18
675′
16
20
700′
16
20
725′
16
20
750′
16
20
775′
16
20
800′
16
20
825′
16
20
850′
16
20
875′
16
20
900′
16
22
925′
16
22
950′
16
22
975′
16
1000′
16


Connect With Us