27. June 2011 09:24
Looking for a PDU to fit your project’s requirements? Needing something a little different than the normal off-the-shelf solution? Yes, there are manufacturers that are able to tailor a solution that can fulfill your particular requirements. What are the key questions to ask a PDU manufacturer when looking for this type of solution?
- What are your company’s capabilities?
- Does your company complete the design and engineering work in-house?
- Is your company experienced in providing both AC & DC solutions?;
- Are your products UL listed?.
- Does your company have a minimum purchase amount for a customized solution?.
- Can your company provide examples of customized solutions that you have manufactured?
It’s important to remember that there are companies such as API Power & Systems Solutions that have the engineering and manufacturing capabilities/expertise to provide solutions that are designed to fit your needs rather than you trying to fit someone’s off-the-shelf solution…..always be sure to weigh your options and don’t settle for less!
22. June 2011 10:45
Let's face it, load calculation can be a demanding task. Let API Power & Systems Solutions do the work for you but utilizing our Three Phase Load Calculator. Simply select your input voltage, enter load values, and voilá the tool instantly calculates Total Power and Line Current.
Go ahead and give it a try! SPMS_load_calculator.xls (788.50 kb)
14. June 2011 17:03
If Circuit Breakers and Fuses are designed to perform the same essential function - what is the big difference?
Circuit breakers and fuses employ two separate types of technology to protect against sudden, large excesses of electrical current, also known as circuit overload.
Why should I be concerned with circuit overload? Circuit overload is the term given to identify a highly undesirable circumstance when more amperage is put across an electrical wire or circuit than it can safely handle. When this occurs, a number of hazardous conditions become concerns including; potentially destroying electrical equipment, extreme heat, and electrical fire.
Circuit Protection via Fuse - A fuse contains a metal filament through which electricity must pass to "complete the circuit." As electricity passes, the fuse is constantly working to detect the amount of current being transmitted. If current reach suddenly becomes too high the metal filament will melt, disrupting the flow of electricity and shutting down excess equipment. After the filament of a fuse has melted there is no way to repair the fuse, it must be replaced .
Circuit Protection via Circuit Breaker - Circuit breakers work by detecting current via pilot device and are able to turn themselves off once current reaches levels that are too high. Circuit Breakers come in a variety of different types ranging from low-voltage to very high voltage models. When current exceeds what the circuit breaker can handle the breaker will automatically "switch off" electricity. After the problem is identified circuit breakers can be easily switched back on and require no replacement.
Pros and Cons - Arguably , there are several pros and cons associated with each of the technologies. Fuses, generally far less expensive, posses greater safety concerns and provide a greater opportunity for human error to occur. Fuses must also be replaced every time an overload is experienced. Circuit breakers, typically considered to be safer and "less hassle" option do not need to be replaced after an overload, however, the technology may also come with a higher price tag in tow. Electricians are best qualified to determine whether fuses or circuit breakers are better for a particular electrical installation.
3. June 2011 13:32
API's focus in creating the new EPS module for 7832 series DC PDU
Today’s network managers primary objective is to manage power utilization in the most efficient and effective means possible, and one way to achieve these objectives is to implement equipment that provides remote control and monitoring over a network. By monitoring the status of outlets, network managers get a picture of their operation and its moment by moment condition. Employing SPMS DC PDU’s with EPS modules, Network Mangers now have the capability to remotely observe the status of each outlet, as well as, remotely control individual outlets based on demand and priority.
The 7832 DC PDU capabilities work in concert to support the network manager’s utmost objective of maintaining data availability and quality of service in data centers or any other type of Power Distribution application where reliable DC power application is required. Basically, the Electronic Power Switch is an electronic circuit protection device. Being electronic, it has certain advantages over and above a mechanical circuit breaker and fuses. As an electronic device the EPS has no moving parts to wear out – an EPS can be remotely controlled to switch on and off for over a million cycles without wearing out components. Since the EPS has no internal mechanism or contacts it is not subject to arcing or contact corrosion or oxidation, and thereby, eliminates the requirement for periodic or preventive maintenance. And the EPS provides a status indication of its output state which is used by the controller to verify command state or a notification of a tripped condition.
The EPS incorporates MOSFET devices as the power switch which provide the advantages as noted above, however, if overstressed they will fail and they’re failure mode is a short. To mitigate this undesirable failure mode several measures have been taken in the new EPS card. Firstly the EPS module has enhancements to maintain the MOSFET within its safe operating area to minimize stress on the MOSFET particularly when turning on into a high bulk capacitive load. Secondly the new device has a very fast reaction time to short circuit conditions. The card’s instant trip mechanism will respond to an over current above 200% of rated current within 1msec again minimizing the stress on the MOSFET as well as protecting the load. Thirdly the EPS card incorporates Transient Voltage Suppressors to protect the MOSFET from over voltage surges. Just as a circuit breaker or fuse the EPS incorporates a trip delay (see chart) within the 120% to 200% of rated current to allow for typical transients and surges during normal operation. Once the EPS detects an over current and the condition continues beyond the delay period the EPS will declare a fault or trip condition by turning off the MOSFET and setting a status flag to indicate a fault condition as been acted on. To recover from a fault or trip condition the EPS must be commanded off. (This is handled in the 7832 PDU by way of the Retry command.)
How to apply the EPS in your application. (Reference configuration chart.)
Size the EPS to your known load. If you know the load characteristics chose the module from the chart noting the Max Bulk Capacitance. If you are not sure of the bulk capacitance rating for a given load chose a module with the desired current rating and test in your application. If the EPS trips when attempting to turn on into the load try an EPS with the next higher current rating. (Insure the wiring and equipment can accommodate the higher current rating.) If this second attempt was not successful then contact technical support for further assistance.
Download the Reference Configuration Chart Now! EPS_Module_Configurations.pdf (19.68 kb)