Allen Bradley 1606 Power Supply Selection Guide

Generally, whenever we’re specifying the requirements of a given system or equipment, choosing a power supply is usually among the last bit of the puzzle. Like in a PLC system, you will often be keen about the processor capability, the memory size…etc, but rarely will you get excited when a more efficient and reliable power supply hits the market. However, the power supply is one piece of hardware that you should never skip out whenever you’re specifying the requirements of your system. It plays a crucial role in ensuring that your system is operating efficiently over the long run.

Hence, it is important you do a little homework before you determine the power supply required by your system or equipment. Most often, the only feature taken into consideration when deciding on a power supply is its power rating. But there are many other factors which should be considered as well. In this article, we’ll be going over all the points that you should take into consideration when deciding on the right power supply for your system, specifically the power supplies within the Allen-Bradley 1606-Series.

Allen-Bradley 1606 Power Supply Overview

The 1606 power supplies are a series of Switched-Mode power supplies by Rockwell Automation. They are designed and manufactured to meet almost all single and three-phase application requirements. Also, the 1606 power units can accept wide ranges of both DC (Direct Current) and AC (Alternating Current) input voltages, and they are tested to comply with global safety standards. A typical 1606 power supply is intended for general power applications such as instrumentation equipment, industrial control, communication, and office equipment. However, it is advisable not to use the 1606 power supplies in safety-critical operations, especially those in which equipment malfunction may threaten human life or cause severe personal injury.

Rockwell Automation provides a variety of 1606 power supply solutions, which include: (i) 1606-XLS Performance Power Supplies; (ii) 1606-XLE Essential Power Supplies; (iii) 1606-XLP Compact Power Supplies; (iv) 1606-XLB Basic Power Supplies; (v) 1606-XLX Regional Power Supplies; (vi) 1606-XLD DC-DC Converters. These products are all designed for high-performance and reliable operation. So, if you’re looking for a compact or a standard product that is cost-effective, with minimal space requirements, and can cover a broad range of applications, then selecting a power supply within the 1606-Series could be an excellent fit for your unique power needs.

Selection Criteria

As part of the evaluation and selection process, you should consider the following features whenever you are choosing an Allen-Bradley 1606 power supply.

A) Wattage

The most important feature to consider when selecting an Allen-Bradley 1606 power supply is the number of watts required, often referred to as the power rating. The exact power wattage of a system is dependent on its components. Hence, you first need to determine the number of devices or components in the system and the power requirements of each. This information is essential in determining the power rating and the number of power supply units required.  

Ideally, the wattage of the power supply unit should slightly exceed the power requirements of your system. This is because a 1606 power supply will work best when it’s left with a little breathing space, which prevents it from overheating. For example, if you want your system to operate with maximum efficiency, the selected 1606 power supply should run between 50% and 80% of its peak power output.

Note, the wattage of the power supply should not be 20% higher than the required amount. As when the wattage goes overboard, your system will be less efficient particularly when it is not under heavy load or when carrying out tasks that aren’t CPU intensive. It is advisable that you select a 1606 power supply with 60% of its maximum power capacity, so as to achieve optimum efficiency.

B) Efficiency Rating

The efficiency rating of a 1606 power supply is very important because higher-efficiency power units tend to consume less power and they generate less heat- which contributes to reduced power wastage in terms of heat and less fan noise (for cooling purposes). For instance, if you select a 1606 power supply with an efficiency of 80% then it will provide 80% of its rated wattage as the power to your equipment or system while losing the remaining 20% as heat. The efficiency of Allen-Bradley power supplies within the 1606-Series is as follows:

  • 1606-XLS Performance Power Supplies: They have an efficiency rating of between 90.0% to 95.4%.  
  • 1606-XLE Essential Power Supplies: The efficiency of the power supplies available in the 1606-XLE Series varies between 84.5% to 95.6%. 
  • 1606-XLD DC-DC Converters: Their efficiency varies between 90.5% to 95.1%. 
  • 1606-XLP Compact Power Supplies: The efficiency rating ranges between 77.2% to 91.0% 
  • 1606-XLB Basic Power Supplies: The power supplies within this series have an efficiency of between 90.6% to 93.8%. 
  • 1606-XLX – Regional Power Supplies: There are two power supplies available within this series namely 1606-XLX120EE with an efficiency rating of 90.5%, and 1606-XLX240EE whose efficiency rating is 91.4%. 

C) Modularity

A modular power supply allows you to easily organize your power cables, hence, you can achieve neat and simple power connections. The main benefit of a modular power supply over a non-modular (which comes with fixed cables) is that it has reduced cable clutter. This leads to better airflow, and a cool working environment for the hardware components of your system both figuratively and literally. Modular power supplies are also more portable. Hence, if you’re looking for flexible power connections, less cable clutter, and portability then you should select a 1606 modular power supply.

Note, modular power supplies have their set of drawbacks. For instance, each power connection is likely to increase impedance on the entire circuit, potentially making your power supply unit less efficient. Even though modular 1606 power supplies have improved over time, their power connections cannot be as efficient as straight power wires. But for most users, tidy power connections with improved airflow outweigh the slight drop in efficiency, especially in cases where space is a constraint.

Nevertheless, instead of having a fully-modular power supply (all the cables are removable), you can have a semi-modular power supply with certain non-removable cables permanently attached at the back of the unit. The permanent cables are the necessary ones, which means with this design you can expand your power connections and you will not have any unused cables lying around.

Also, modularity goes hand-in-hand with compactness for space-saving. For example, the 1606-XLP Compact Switched-Mode Power Supplies are the most ideal solutions when saving critical space is a key objective for your application. This is because the power supplies available in the 1606 XLP-Series are smaller(compact) but very efficient, thereby providing a cost-effective way to save on space while delivering safe and reliable power. Likewise, the 1606-XLS Series provides you with significant space-saving, with a design that features smaller per watt profiles. For instance, the 1606-XLS120E – 5 power supply is 40mm wide while the 1606-XLS240E – 10 power supply is 60mm wide.

D) Compatibility

It is important that you select a 1606 power supply that is compatible with your equipment, system, or machine. Otherwise, you can select a very efficient power supply that has the required amount of wattage to run your machine. But you find that it is not compatible with the make and model of your machine. Also, you should consider the compatibility of the provided power cables with your system, for direct connections.

E) Certifications and Standards Compliance 

Ensure that you check if the 1606 power supply you’re to select is certified by the appropriate agencies. The selected power supply should comply with the required standards before installation, this will ensure safety and reliability when in operation.

The various certifications and standards that are required for the Allen-Bradley 1606 power supplies include CE certification, UL 508 listing, UL 60950-1 listing, UL 61010-2-201 listing, IEC 60950-1 CB-Scheme, IEC 61010-2-201 CB-Scheme, IECEx, ATEX, Class I Div. 2 HazLoc, DNV GL Marine, ABS Marine, EAC Registration, NEC Class 2, EN 61000-3-2 Harmonics (PFC), EN 61000-6-1(Immunity for residential), EN 61000-6-2 (Immunity for industrial), EN 61000-6-3(Emission for residential), EN 61000-6-4(Emission for industrial environments), and EN 55011 / EN 55022 class B (Disturbance characteristics).
Note, each power supply within the 1606-Series is not required to comply will all of the aforementioned certifications and standards. Hence, check the specific compliance requirements for the power supply you’re considering.

F) Special Modules

Allen-Bradley provides several Special modules within the 1606 power supply-Series. They include:

  • The Buffer Modules: which provide a short power function in case of brownout conditions- the Brownout Buffer Module. The buffer modules are also used to buffer load currents during switching events, load peaks, or typical main faults. Allen-Bradley provides the 1606-XLBUFFER Brownout buffer module. 
  • Redundancy Modules: They are used to decouple or manage dual 1606 power supplies, and to provide backup, this ensures high productivity and all-time availability of your system. A redundant 1606 power supply is necessary for applications that have the highest demands of operational reliability. As it prevents the occurrence of system downtime in case one power supply unit fails.

The available modules within this category include: (i) N+ 1 Redundant capable module with NEC Class 2 feature, catalog number 1606-XL60DR. This module should be used with two identical power supplies so that it can provide the N+1 redundancy. (ii) N+ 1 Redundant capable modules namely 1606-XL120DR and 1606-XL240DR. The two modules should be used with a pair of identical power supplies. (iii) Dual N+1 redundancy Module- 1606-XLRED20-30. This module needs to be used alongside 30 and 20 A power supplies (or smaller). (iv) Single N+1 redundancy-1606-XLRED40, can only be used with 40 A power supplies (or smaller).

  • DC to DC Converter Modules: These modules can either be an electromechanical device or electronic circuit which converts DC source currents from one voltage level to another and stabilize the voltage.  

If your application has an improper or unstable voltage supply then a 1606 DC-to-DC converter would be an ideal choice. As unstable or improper voltage levels can lead to malfunction and even degradation of your system. The available 1606 DC-to-DC converter modules by Allen-Bradley include: (i) 1606-XLDC92D with NEC Class 2 feature; (ii) 1606-XLDF120E; (iii) 1606-XLDD240E; (iv) 1606-XLDF240F

G) Consider the Rails

When selecting a 1606 power supply be sure to consider the rails. This can be a confusing feature, especially because the Allen-Bradley specifications sheets usually have the rails listed as +12 V rails…etc. Well, a rail is a pathway on a circuit board through which the system draws power. Rails indicate the number of “paths” supplying power to the connected system or machine. A single rail 1606 power supply has only one pathway. Such a power supply can only provide the full wattage of the unit from one rail to all the connected components. While a multi-rail power supply distributes power among several rails.

Single rail 1606 power supplies are preferred as every connected component receives ample power for its operation. However, a drawback with single rail power supplies is that they make your system more prone to power surge risks. On the other hand, multi-rail 1606 power supplies can handle power surges, as each rail has a built-in short-current and over-current prevention system. Hence, if you select a single rail power supply, you should consider installing reliable surge protectors.

H) Mounting

Power supplies within the 1606-Series are either DIN rail, direct wall or panel mounted. For this reason, you will need to select the mounting brackets that are compatible with your power supply, and depending on the type of mounting being used.

The available mounting brackets with the 1606 power supply Series include: (i) Mounting brackets for panel or direct wall mounting without DIN rail namely 1606-XLA-UPSC, 1606-XLA-W45, 1606-XLA-XLE, 1606-XLB, and 1606-XLC. (ii) Mounting brackets used in sideways installation either with or without a DIN rail. They include 1606-XLA-S37, 1606-XLA-S44, 1606-XLA-S76, 1606-XLA-S85.


As noted in this article, the power supply plays a key role in the proper and reliable functioning of your machine or system. Hence, whenever you’re upgrading any of the mentioned 1606 power supplies or getting a new one, ensure that you consider all the factors outlined in this article.

No matter the budget, always invest in the best 1606 power supply that you can afford. As deciding on the right power supply for your equipment or system, will keep your system operating efficiently for a longer period of time. Ultimately, you’ll have cost savings in terms of increased productivity, reduced breakdowns, and repairs.

Posted on:
DO Supply Inc. makes no representations as to the completeness, validity, correctness, suitability, or accuracy of any information on this website and will not be liable for any delays, omissions, or errors in this information or any losses, injuries, or damages arising from its display or use. All the information on this website is provided on an "as-is" basis. It is the reader’s responsibility to verify their own facts. DO Supply Inc. is not an authorized distributor and is not in anyway affiliated with Rockwell Automation. DO Supply Inc. makes no representation as to your ability or right to download, obtain, or use any firmware provided by the product's manufacturer. To the extent you wish to use such firmware, it is your responsibility to comply with the terms of any applicable license or other such agreement related to the download, installation, or use of the firmware. DO Supply makes no representation that the version of the firmware that is installed on any product it sells is appropriate for your needs or use. Further, DO Supply Inc. does not sell, re-sell, or license software that may be needed to operate certain hardware and customers must obtain any necessary software licensing, maintenance, or upgrades from the manufacturer or other authorized source. To the extent any of the products sold by DO Supply requires software for operation, you acknowledge that DO Supply does not sell or license such software and that it is solely your responsibility to obtain the software or a proper license to use it from authorized sources.
Post author

Leave a comment

Your email address will not be published. Required fields are marked *