Q: 2. What is NEC Class II?

NEC Class 2 Power Supplies NEC (National Electrical Code) in North America classifies the electrical circuits in different Groups. The electrical Limits for NEC Class 2 circuits are Maximum 60V, 100W and 8A. Also for abnormal Operation These Limits are valid and Need to be verified. NEC Class 2 circuits are considered as not dangerous related to fire hazard and electrical shock The Advantage of Class 2 circuits are: Less wiring efford (no cable conduits) Less testing efford for application approvals. For NEC Class 2 circuits an external approval is madatory. A self-declaration is not possible.

Q: 4. How can you split the 2 channels on the output voltage connection?

Using splitter, EBC162 ayou can split the output voltage of the DN4218 . The DN4218 has an A-coded electrical connection, while the other DN42xx power supplies have L-coded connections.

Q: 5. Why does my DN42xx power supply make a humming noise?

Under no load, the power converter generates a frequency that results in a humming noise. This is a natural byproduct of the device's operation and falls within the normal operation.

Q: 6. What is the benefit of using the L-coded power supplies with ifm PerformanceLine IO-Link masters?

The L-coded power supplies are designed to match the pinout of US/UA on the AL14 family PerformanceLine IO-Link masters, so that each has an independent channel and a simple patch cord can be used.

Question 1

1. What has to be observed when connecting power supplies in parallel?

Accepted Answer

It is generally recommended to be particularly cautious when connecting power supplies in parallel.

It is necessary to distinguish between parallel connection to create redundancy and parallel connection to increase power:

Creation of redundancy:

The parallel connection of two identical devices is only allowed for setup of 1+1 redundant systems. Note that the setting of the output voltages of both power supplies must be exactly identical.

Increase of power:

Parallel connection without further precautions is only allowed to cover inrush peaks with a switch-on duration of <10%.

Moreover, only the DN4034 may be connected in parallel without taking further precautions.

Diode modules are preferred for parallel connection.

If a diode module cannot be used, all DN40xx may be connected in parallel under the following conditions:

Only two identical power supplies may be connected in parallel.
The adjusted output voltage must be exactly the same on both power supplies. From 01 V precise.
The first cable meter (up to the first terminal) to which the power supplies are connected in parallel must be identical for both power supplies.

The same cable type, the same diameter, the same cable length.

Note: The DN42xx series cannot be connected in parallel.

Question 2

2. What is NEC Class II?

Accepted Answer

NEC Class 2 Power Supplies

NEC (National Electrical Code) in North America classifies the electrical circuits in different Groups.
The electrical Limits for NEC Class 2 circuits are Maximum 60V, 100W and 8A. Also for abnormal Operation These Limits are valid and Need to be verified.
NEC Class 2 circuits are considered as not dangerous related to fire hazard and electrical shock
The Advantage of Class 2 circuits are:
- Less wiring efford (no cable conduits)
- Less testing efford for application approvals.
For NEC Class 2 circuits an external approval is madatory. A self-declaration is not possible.

Question 3

3. What should the operating voltage be configured to?

Accepted Answer

The operating voltage should be configured based on the specific use case and not soley on the maximum output voltage, as it does impact efficiency and overall power consumption.

When configuring the supply voltage of your power supply, you need to be sure to take voltage drop into account.

In order to assure that the correct voltage is received at the point of work, cable resistance can be accounted for in the configuration of the system.

While an exact calculation of voltage drop is recommended for an installed system, an approximation of the loss due to resistance can be achieved through the example formula below.

Voltage drop calculation

DC single phase:
V_{drop (V)}= I_{wire (A)} x (2 x L_(ft) x R_{wire (Ω/kft)} / 1000_(ft/kft))

3-phase:
V_{drop (V)}= √3 x I_{wire (A)} x (L_(ft) x R_{wire (Ω/kft)} / 1000_(ft/kft))

V = voltage
I = current (Amps)
L = length (ft)
R = wire resistance (Ω/kft)

Calulation example using EVC003 with IFT245:

I_{wire (A)}= 25 mA per the current consumption of the IFT245
L_(ft)= 32.8 ft per the length of the EVC003
R_{wire (Ω/kft)}= 16.14 Ω per 1000 ft based on the gauge (22 awg) of the EVC003

DC single phase:
V = 0.025 A x (2 x 32.8 ft x 16.14 Ω/kft / 1000 ft/kft) = 0.025 A x (1.06 Ω) = 0.03 V

3-phase:
V = √3 x 0.025 A x (32.8 ft x 16.14 Ω/kft / 1000 ft/kft) = √3 x 0.025 A x (0.53 Ω) = 0.23 V

Question 4

4. How can you split the 2 channels on the output voltage connection?

Accepted Answer

Using splitter, EBC162 ayou can split the output voltage of the DN4218.

The DN4218 has an A-coded electrical connection, while the other DN42xx power supplies have L-coded connections.

Question 5

5. Why does my DN42xx power supply make a humming noise?

Accepted Answer

Under no load, the power converter generates a frequency that results in a humming noise. This is a natural byproduct of the device's operation and falls within the normal operation.

Question 6

6. What is the benefit of using the L-coded power supplies with ifm PerformanceLine IO-Link masters?

Accepted Answer

The L-coded power supplies are designed to match the pinout of US/UA on the AL14 family PerformanceLine IO-Link masters, so that each has an independent channel and a simple patch cord can be used.

Frequently asked questions about the DN42 field mountable power supplies