LIGMAN TRAINING CONSTANT CURRENT AND CONSTANT VOLTAGE DRIVERS
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SHOULD I USE CC OR CV? • Wherever possible, use Constant Current drivers • LEDs are designed for constant current circuits, and the CC ensures a strong stable lumen output • Constant Voltage SELV drivers ensure that the supplied Voltage does not exceed safety levels following IEC60364-7-702 • Constant Voltage circuits need current limiting resistors to prevent thermal runaway. Without a current limiting resistors the LED have a lower life time. • When calculating the driver size and power, care must be taken for Voltage drop (see following slides)
WHICH LUMINAIRES ARE CV COMPATIBLE? • The following luminaires contain current control diodes, which mean they can be used with 24V DC Constant Voltage drivers:
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OREGON 1
LBX 2 & 4
NEVADA
LADOR 1
UTAH 1 & 2
PATCHI 1 & 2
ALDO
IF THE CUSTOMER WANTS TO USE LESS DRIVERS? • The following luminaires can be used with Constant Voltage drivers: PRODUCT ID
PRODUCT SERIES
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
OR-60894
OREGON 1
1.5
3
4.5
6
7.5
9
10.5
12
13.5
15
16.5
18
19.5
21
22.5
24
25.5
27
28.5
30
OR-60895
OREGON 1
1.5
3
4.5
6
7.5
9
10.5
12
13.5
15
16.5
18
19.5
21
22.5
24
25.5
27
28.5
30
ALD-30001
ALDO 1
6
12
18
24
30
36
42
48
54
60
66
72
78
84
90
96
102
108
114
120
ALD-30011
ALDO 1
12
24
36
48
60
72
84
96
108
120
132
144
156
168
180
192
204
216
228
240
ALD-30121
ALDO 2
18
36
54
72
90
108
126
144
162
180
198
216
234
252
ALD-30111
ALDO 2
24
48
72
96
120
144
168
192
216
240
ALD-30131
ALDO 2
36
72
108
144
180
216
252
ALD-30171
ALDO 3
48
96
144
192
240
LB-40437
LBX
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
LD-50002
LADOR 1
6
12
18
24
30
36
42
48
54
60
66
72
78
84
90
96
102
108
114
120
LD-50012
LADOR 2
13
26
39
52
65
78
91
104
117
130
143
156
169
182
195
208
221
234
247
260
LD-50022
LADOR 3
18
36
54
72
90
108
126
144
162
180
198
216
234
252
LD-50032
LADOR 4
36
72
108
144
180
216
252
NE-60834
NEVADA 2
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
NE-60835
NEVADA 1
4
8
12
16
20
24
28
32
36
40
44
48
52
56
60
64
68
72
76
80
PAT-30001
PATCHI 1
6
12
18
24
30
36
42
48
54
60
66
72
78
84
90
96
102
108
114
120
PAT-30011
PATCHI 1
12
24
36
48
60
72
84
96
108
120
132
144
156
168
180
192
204
216
228
240
UT-50554
UTAH 1
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
UT-50564
UTAH 2
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
As a general rule, always allow a 20% margin when selecting the driver A32091
Driver ND 20W non IP
A32191
Driver ND 50W non IP
A32291
Driver ND 100W non IP
A32391
Driver ND 150W non IP
A32491
Driver ND 200W non IP
A32591
Driver ND 300W non IP
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IF THE CUSTOMER WANTS TO USE CV DRIVERS FOR UNDERWATER? • All underwater luminaires already come with remote CC drivers • The underwater luminaires do not have current limiting diodes so cannot be used with constant Voltage circuits today.
WHAT IS VOLTAGE DROP? • Electrical cables are like resistors, the electrons in the copper bounce around preventing the current to travel effectively, see herefor more information • Why is this a problem? If the Voltage drops too low the LEDs will stop working • The resistance of the cable depends on many factors: the quality of the copper, stranded or solid, wire diameter, length, temperature, coiling and its condition • AC Voltage has more Voltage drop that DC Voltage • The Voltage drop can be calculated here • For example, a 1mm copper cable will lose 0.029V over 1m at 24V DC / 700mA
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WHAT IS THE MAXIMUM VOLTAGE DROP ALLOWED? • “It is recommended that the voltage drop should be less than 5% under the fully loaded condition” • In this case, if we use 24V DC as our standard for LED lighting, the maximum Voltage drop is 1.2V • Typical wiring from a driver to an LED board is around 0.5mm dia(0.25 –1mm is common) • Using the above information, for a 350mA LED, the maximum distance from the driver allowed is 20m. For a 700mA LED, the maximum distance is 10m • Constant current circuits are less affected by Voltage drop because they compensate by increasing the Voltage supplied in order to maintain a constant current, until the maximum power is obtained
CC VS CV DRIVERS Constant Current
Constant Voltage
• LEDs work on constant current • Provides constant lumen output
• Good for unknown quantity of luminaires • Ideal for underwater applications when used with current limiting diodes
• More expensive than constant Voltage circuits
• Susceptible to thermal runaway • Sensitive to Voltage drop
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WIRING CONSTANT CURRENT AND CONSTANT VOLTAGE CIRCUITS Constant Current luminaires must be wired in series
Constant Current driver 20W500mA 3-57V
Constant Voltage luminaires must be wired in parallel
Constant Voltage driver24V DC20W
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Maximum length allowed depends on driver power available
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Maximum length allowed depends on number of luminaires, current, temperature etc
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