9This project was a nightmare from the start. Medical industry rules and regulations an arduous task. Not the common inverter/solar install but rather generator/ ups. Big machines 30kva single phase generator backed up by 30kva Tescom double conversion Ups battery voltage 256v lead carbon 40 x 50ah connected 20 in series 2 banks in parallel.

Awaiting delivery for Tescom 30kva Ups and 30kva isolation transformer from Ismur in Turkey. DB board done and generator connected and tested. I was impressed by the ATS(Deep Sea Electronics) on the generator 15sec from start to power delivery. 40kva load bank to test the installation.

Sorry for the red dots on the energy meters but the practice numbers are proprietary information i had to get permission to post these pictures on this forum.

 

I got this picture from the internet to show the Tescom 30kva Ups exactly this one i am waiting for.

Man this looks intimidating...Pity no Lithium drop In replacement available for the battery side. 

2 hours ago, Steve87 said:

Man this looks intimidating...Pity no Lithium drop In replacement available for the battery side. 

@Steve87 these lead carbon batteries are actualy rated for 5000cycles and they could be discharged below 50% without long term damage. They are going to idle as it will cover max 60 sec until generator takes over. It is actually for emergency standby should the genset fail. The pathology laboratory requires seamless power transfer due to the sensitive equipment and freezers that store samples. 

 

Makes a lot of sense. It's basically an insurance policy for the stop gap between change overs. However, knowing how lead batteries work also keeping them on a high float can also be destructive. But I guess it's what they have existing so make use of it. 

23 hours ago, TaliaB said:

Medical industry rules and regulations an arduous task. Not the common inverter/solar install but rather generator/ ups.

What is so special about the rules and regulations regarding this particular place that prevent them of using solar? I see many other medical places with solar panels on the roofs. 

6 hours ago, Steve87 said:

Makes a lot of sense. It's basically an insurance policy for the stop gap between change overs. However, knowing how lead batteries work also keeping them on a high float can also be destructive. But I guess it's what they have existing so make use of it. 

I don't have any knowledge with lead carbon but normal start cycle lead acids actually work very well for years when used for a burst like in cars. Charged immediately after supplying load when genny runs. 

Also part of maintenance should be regular test runs when the grid is on. 

This 1min period suits lead acid very well. Just my recent experience with 1 car is that the 1st battery ladted over 6 years and I am not on over 5 years. 

With maintenance on such a critical application I would think it suits lead acids very well. Such a system could even employ a main and back up set like in most critical services in 24/7 factories as well as main transmission power lines protection DC supplies. 

Edited July 19, 20232 yr by Scorp007

42 minutes ago, PowerUser said:

What is so special about the rules and regulations regarding this particular place that prevent them of using solar? I see many other medical places with solar panels on the roofs. 

The SA National Standards Electrical Guidelines 10142 SANS is the only permissible guideline to follow and contains a section on minimum power requirements for a medical facility. It refers to a power supply from a “safe source” such as a generator combined with an ups, which shall be energised in the case of a failure of the usually supplied sources of power. The Occupational Health and Safety Act 85 of 1993 forms the basis of risk assessments regarding, for among others, power outages and emergency stanby power generation in medical facilities. I do not procure the equipment to be installed i do the installation run the test and issue coc. Your normal installation electrician are not allowed to issue a coc in any medical facility it must be a master electrician.

7 hours ago, Steve87 said:

However, knowing how lead batteries work also keeping them on a high float can also be destructive.

The Tescom ups actualy performs a self test on the bateries that is programmed for specific time intervals. The only problem i have to this approach is that many modern, or smart, UPS units can complete a ‘self-test’ operation on the batteries within the unit. Often, these self-tests take place automatically when the UPS is turned on or they can be programmed to take place at preferred intervals.  One of the most common ways the self-test function is completed by temporarily discharging the batteries to determine how long they would run. When a UPS is performing a self-test using the discharging method, UPS systems are designed to measure the voltage that the string of batteries is providing. During the duration of the test, the UPS will measure the starting voltage and ending voltage of the string to determine if the DC voltage remains within an acceptable tolerance. Should the DC voltage dip below a threshold limit during this time, it will cause the UPS to end the self test, and generate an alarm. The unit does not determine how many volts are being produced by a single battery. When a battery within the string is starting to fail, it may continue to pass voltage along even if the individual cell is not within the recommended voltage range. Essentially, this could lead to a battery string to pass a self test, even if there is a failing cell. 

On 2023/07/18 at 7:43 PM, TaliaB said:

Awaiting delivery for Tescom 30kva Ups

Undergoing test in Turkey they sent me the picture today should arrive within 10 weeks. The batteries are on shelf for testing purposes. Once done they come in a steel enclosure. 60 x 65ah lead carbon 2 banks of 30 in series 2 banks paralleled. Weight of 1 x battery 15.21kg total weight of batteries and enclosure 950kg. 380volts 130ah 49kwh.