3. Installation

3.1. Inspection

Carefully unpack the MagnaLOAD and accessories saving all packing materials and included enclosures. Inspect the product for possible shipping damage. Check that there are no broken knobs or connectors, the external surface is not scratched or dented, the meter faces are not damaged, and all controls move freely. Any external damage may be an indication of internal damage. If there is any damage, notify the shipping carrier and Magna-Power immediately: www.magna-power.com/support.

The following parts are included with all MagnaLOAD models:

  • ARx Series MagnaLOAD
  • USB cable (Type A to Type B)
  • Rear metal cover with required fastening hardware
  • Qty (4) rear support brackets
  • Qty (32) 10-32 screws
  • Qty (16) 10-32 flat washers and lock washers
  • USB drive with software, drivers, and digital documentation
  • Calibration certificate with Declaration of Conformity
  • AC input cable

3.2. Rack Installation

The ARx Series MagnaLOAD is intended for rack-mount installation, designed to fit in a standard 19” equipment rack. When installing into a rack, both front and rear support is required. Fixed rear rack-mount support brackets are provided for the the product’s rear. The unit should be horizontally mounted.


The ARx Series MagnaLOAD is too heavy for one person to safely lift and mount. To avoid injury, always seek assistance from a co-worker before trying to lift and install the product into a rack.

The following steps, which reference Figure 92, should be followed when installing the ARx Series MagnaLOAD into a rack:

  1. Install 16 clip nuts on the rack frame; 8 for front support and 8 for rear support.
  2. Install the rear rails onto the MagnaLOAD, but not the mating rear rail ears.
  3. While providing support for the MagnaLOAD, fasten the front ears to the rack using the provided 10-32 screws.
  4. While continuing to provide support for the MagnaLOAD, attach the mating rear rail ears onto the rear rails using SCREW TYPE HERE. Adjust the position of the rear rail ears to align snuggly with the rear rack rails before tightening.
  5. Fasten the rear ears to the rack using the provided 10-32 screws.

Figure 79: Rack mount installation diagram for the ARx Series

3.2.1. Cooling Requirements

The rack-mount 6.75 kW ARx Series MagnaLOAD features integrated fans that pull in cool air from the front and sides and exhausts warm air from the rear. Air intake from only the front and sides of the product allow two or more MagnaLOAD to be stacked with zero clearance between units. Equipment racks housing the MagnaLOAD should be equipped with either an open back or cabinet fans to remove heat generated by the MagnaLOAD. For fully enclosed cabinets, Magna-Power recommends fresh air intake from the bottom of the cabinet and exhaust at the top.

The stand-alone 13.5 kW to 40.5 kW ARx Series MagnaLOAD features integrated fans pull in cool air from the front and exhausts warm air from the top and rear. At least 18 inches (46 cm) of clearance should be provided in rear of the unit for proper exhaust.

The following table provides the maximum heat produced for each power level. In addition, the table provides Magna-Power’s recommended cabinet air-flow when installing the rack-mount 7.5 kW ARx Series MagnaLOAD in a fully enclosed cabinet:

ARx Series Rated Power Level Maximum Heat Produced Recommend Cabinet Air Flow
6.75 kW 25.6 kBTU/hr 1200 CFM
13.5 kW 51.2 kBTU/hr N/A
20.25 kW 76.8 kBTU/hr N/A
27 kW 102.4 kBTU/hr N/A
33.75 kW 128.0 kBTU/hr N/A
40.5 kW 153.6 kBTU/hr N/A


Do not block the air intake on the front or sides of the instrument, nor the MagnaLOAD‘s exhaust. Blocking these vents could cause the product to overheat.

3.3. AC Input Connection

A single-phase AC input connection is used to provide a ground reference and power for the MagnaLOAD‘s fans and control circuits. The AC input power requirements are defined for each MagnaLOAD on its product rating label. The AC input requirements are further defined in this section.

Connect the provided power cord to the IEC 60320 AC power receptacle on the rear of the MagnaLOAD. The type of connector used depends on the MagnaLOAD‘s AC input power. For low-power units, an IEC 60320 C13 receptable is used, as shown in Figure 93. For high-power units, an IEC 60320 C19 receptable is used, as shown in Figure 94.

Figure 80: ARx Series IEC 60320 C13 AC power receptacle

Figure 81: ARx Series IEC 60320 C19 AC power receptacle


The power cord provides a chassis ground through a third conductor. Be certain that your power outlet is of the three-conductor type with the correct pin connected to earth ground.

The following table provides the AC input requirements for the various ARx Series MagnaLOAD power levels:

ARx Series Rated Power Level AC Input Voltage Range AC Input Current Range (Maximum) AC Power Receptacle Style
7.5 kW 85 - 265 Vac 3.5 - 1.2 Aac IEC 60320 C13
15 kW 85 - 265 Vac 11.8 - 3.8 Aac IEC 60320 C13
22.5 kW 85 - 265 Vac 15.3 - 4.9 IEC 60320 C13
30 kW 85 - 265 Vac 18.8 - 6.0 Aac IEC 60320 C13
37.5 kW 187 - 265 Vac 10.1 - 7.2 Aac IEC 60320 C19
45 kW 187 - 265 Vac 11.7 - 8.3 Aac IEC 60320 C19


The AC Input Current Range specified in the table above is relative to the AC Input Voltage Range. For example, referring to the 15 kW ARx Series model, the AC input current will be 11.8 Aac at 85 Vac and 3.8 Aac at 265 Vac. Using a linear interpolation, at 120 Vac the AC input current would be 10.2 Aac.

3.4. DC Input Connection


Disconnect AC power from the mains before attempting any installation procedure.

The input of the ARx Series MagnaLOAD is connected to the DC bus by attaching two cables to the input bus bars, as shown in Figure 95. Magna-Power recommends cables be crimped to ring terminals and securely fastened to bus bars using the included 3/8” bolts, washers, and lock washers. The bus bars contain 3/8”-16 threaded inserts. The recommended torque for the DC connection is 175 in-lbf (19.77 N-m).

A chassis ground reference is also provided on the rear near the DC bus bars, which is tied to the AC input ground. The recommended torque for the ground stud is 55 in-lbf (6.21 N-m).

After connections are made, screw the four standoffs into the back panel and place the protective shield over the connections.

Figure 82: DC input connection for the ARx Series


Make sure DC connections are tight to avoid overheating of the bus bars.

The following table provides the suggested DC ampacities of AWG (American Wire Guage) copper wire. Paralleled DC cables may be required for larger-ampacity |product_type|s. Ampacity ratings ar based on single conductor in 25 °C ambient free air, with a conductor rated for 60 °C.


For DC cabling, Magna-Power highly recommends flexible General Cable Carol® Brand Carolprene® cable, used by Magna-Power and many of its customers.

Wire Size (AWG) Wire Size (Metric, Rounded) Maximum Current (Adc)
12 4 mm2 30
10 6 mm2 40
8 10 mm2 60
6 16 mm2 86
4 26 mm2 110
3 30 mm2 130
2 35 mm2 150
1 40 mm2 170
1/0 50 mm2 200
2/0 70 mm2 235
3/0 95 mm2 275
4/0 120 mm2 315

For DC bus connections exceeding 315 Adc, Magna-Power recommends multiple runs of 4/0 cabling in parallel. Custom DC bus work may be required to either extend the MagnaLOAD‘s DC bus bars allowing additional DC wire connections, or to make a direct connection with the DC bus work. With increased cable bundling, the ampacity rating of the DC cables will decrease, as less surface area is in free air to cool the wires.

3.4.1. Remote Sense Connection

Remote sensing is used to improve the degradation of regulation which will occur at the MagnaLOAD inputs terminals when the DC voltage drop from the connected DC source to the MagnaLOAD is appreciable. Compensation is achieved by connected the MagnaLOAD‘s high impedance sense wires to the connected DC source’s input and configuring the MagnaLOAD for remote sensing either from the front panel configuration or by computer command. When enabled, the MagnaLOAD will voltage measurements will be taken from the remote location.

When remote sense is enabled and operating properly, []

Magna-Power recommends 20 AWG wires, with MagnaLOAD‘s positive remote sense terminal to the positive of the DC source and connect the MagnaLOAD‘s negative remote sense terminal to the negative of the DC source.


Always ensure that the positive remote sense lead corresponds to the positive DC bus and, likewise, that the the negative remote sense lead corresponds to the negative DC bus. Connecting sense wires with an incorrect polarity can result in equipment damage.

The MagnaLOAD features Smart Sense Detection to protect the product in the event remote sense is enabled but the sense leads are broken or disconnected.

3.5. External User I/O Connection

The ARx Series MagnaLOAD has a 25-pin External User I/O port located in the product’s rear. The External User I/O connector is a standard female D-Sub 25-pin connector. The removable screw-locks provide means of securing mating connectors with commercially available 4-40 threaded hardware. The torque limit for the screw locks is 2 in-lb (0.23 N-m) applied from the mating face side. The maximum push out force is 20 lb-force (89 N) applied from the mating face side.

Figure 83: External User I/O D-Sub 25-pin connector and pin layout

3.6. Computer Connection

This section describes how to connect various communication interfaces to your MagnaLOAD. Beyond installation, more detailed information about the communication interfaces and programming instructions is described in: Operation: Computer Programming.

3.6.1. USB

3.6.2. RS485

The ARx Series MagnaLOAD supports RS485 communications through an RJ45 connector located on the rear communications panel, as shown in Figure 84. The signals A (Data +), B (Data -), and GND are wired to pins 1, 2, and 7 of the RS485 RJ45 connector, respectively. The remaining pins are electrically disconnected.

Figure 84: RS485 RJ45 connector and pin layout

Connection to a computer can be established using standard Ethernet cable, with one end connected to the MagnaLOAD and the other to a controlling device. The RS485 configuration parameters are as follows:

Parameter Value
Baud 115200
Data bits 8
Stop bits 1
Parity None
Flow Control XON/XOFF

Internally, RS485 operates on a shared communications bus with USB, LXI TCP/IP Ethernet, and IEEE-488 GPIB interfaces; only one interface can be active at a time. If none of these interfaces are connected, the MagnaLOAD defaults to RS485. The presently active communication interface is denoted in the front panel status menu display.


Refer to the ANSI/TIA-568 telecommunications standard for the most common pin-to-pair assignments found on Ethernet cables: T568A and T568B.

3.6.3. LXI TCP/IP Ethernet

Figure 85: LXI TCP/IP Ethernet RJ45 connector and pin layout

3.6.4. IEEE-488 GPIB

Figure 86: IEEE-488 GPIB connector and pin layout

3.7. Electrical Check

Turn on the MagnaLOAD using the black control power switch on the bottom left of the front panel. Immediately after turn-on, the MagnaLOAD undergoes a self-test that check control and input circuitry. The Magna-Power emblem should be displayed during this self-test along with the the word MagnaLOAD.


After turning the unit on, it will take about 5 seconds for the MagnaLOAD to initialize before it is ready for use.

When self-test is complete, the Menu display should show the unit’s Standby status, the voltage meter should show whatever the DC bus voltage is, and the current meter should show 0.000. The fans should be running at a low speed.

If the self test fails, the fans do not come on, or the unit fails to come into standby, power off the MagnaLOAD off and back on with the black power switch. If you continue to have similar issues, contact Magna-Power support for further assistance.

3.8. Firmware Update

Firmware update is achieved via the MagnaWEB software.