When connecting a power supply to a load, it is very important to use wires that are appropriate for the voltage and current.
If sourcing thick wires for high-current applications is difficult, using multiple thinner wires in parallel is a viable alternative.
However, it is crucial to ensure that all wires are of the same type, gauge, and length. Additionally, the contact resistance at all connection points should be minimized and kept as uniform as possible.
Extracted from "Installation of DC Power Supply and remote sensing correctly and safely - CONNECTION OF LOAD"
CONNECTION OF LOAD
Your power supply's stability and ripple noise will be directly affected by its wiring and grounding.
• Use wires thick enough for your application. Use as short a length as possible.
• Select PVC electric wire (105°C) of the proper voltage rating
When connecting to the load, you must consider both the wire's ampacity (current-carrying capacity) and the maximum allowable length. The length is limited by the maximum voltage drop that the remote sensing feature can compensate for (typically 0.5V per wire). See the table below to determine the proper wire gauge.
| AWG | mm2 | Max. current [A] |
|---|---|---|
| 18 | 1.1 | 2 |
| 16 | 1.3 | 7 |
| 14 | 2.1 | 11 |
| 12 | 3.3 | 18 |
| 10 | 5.3 | 23 |
| 8 | 8.4 | 39 |
| 6 | 13 | 67 |
| 4 | 21 | 106 |
| 2 | 33 | 170 |
| 1 | 42 | 209 |
| 1/0 | 53 | 270 |
| 2/0 | 67 | 330 |
| 3/0 | 85 | 350 |
• When connecting multiple loads in parallel, run a separate pair of wires from the power supply terminals to each load.
Good
Proper Connection
Incorrect Connection
Poor Practice
Loads 2 and 3 will experience a larger voltage drop because they are downstream in this daisy-chain configuration. The ripple voltage at these loads may also increase due to the shared wire impedance.
• When connecting to an inductive load (e.g., a motor, solenoid, or relay coil), place a protection diode in parallel with the load as shown. This diode protects the power supply from back EMF (inductive kickback) generated when the load is de-energized. The diode's voltage and current ratings must exceed the power supply's output voltage and current.
• Repeatedly connecting the power supply to a load that may cause discharges or short circuits can shorten the product's service life and may lead to failure. If such conditions are expected, install a protective resistor in series with the output.
In addition, to fully utilize the original performance of a DC power supply, it is important to properly connect and ground it.
Please also see the Technical Knowledge on our website, "Installation of DC Power Supply and remote sensing correctly and safely".
Please note: Failures or malfunctions caused by improper load connection are not covered under warranty.