Electric load help needed. [ DYNALOAD  RBL 400-600-4000 ] - Page 1
Forum section: electronics / testgear

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 06:00:55 pm
content: Hello everyone, first time here.I am looking for someone knowledgeable in electric loads. I need to test this load (DYNALOAD RBL 400-600-4000) to see if it is still good.Electronics stuff that I have done is repairing some motherboards and making a pair of ac -> dc converter and limiter.  also repaired a sound mixing board power supply (changing burnt transformers) .Basically has nothing to do with operating electric loads.Can someone with experience write a few lines about what I can do to test it and see if it works as supposed to?I attach some photos of panel. Thanks very much!At the end I also attached the manual in pdf.Images will be posted in separate posts.

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 06:08:37 pm
content: the manual

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 06:17:51 pm
content: this is booting up with the load disengaged.the voltage and amps stabilise around zero if you wait a bit. anyway, its not hooked to anything.I have a few powersupplies with 5vdc,12vdc and another one at 40vdc. I can find other supplies too if I look around a bit for testing

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 07:19:11 pm
content: UPDATEI went ahead and started testing a small power supply rated 12V-1A.settings used were:NO pulse (i guess it does what it says? draws current in pulses?) did not try that yet properly.For the LOAD ADJUST I used POWER (Constant power mode).Starting with the LOAD ADJUST knob at zero.When activating the DC LOAD it measures a voltage of 17v since there is no load.I brought it up slowly up to 0.25A and voltage went down as expected. at around 1A it was around 12v.When bringing up the amps well over 1.5A (drawing too much current) the SAT led went on indicating saturation?When bringing the load down below 1A the SAT led went out.HERE COME THE PROBLEMS:Everything is fine and all until the load AMPS indicator started to drift upwards by itself until I hear a switch going off inside the unit and all the yellow leds lit up together with the Undervoltage AND the Overvoltage leds....The only solution here is turning off the units main ac switch. Then I turned off the DC load and turned down the load knob before attempting again.After redoing the same procedure it started to drift away sooner than last time and shuts down in the same way.If I wait for a bit before applying the load it takes longer time before the same symptoms, (it drifts away and lits up all the leds (except the over temperature led).If I let it 'cool off' a bit it seems to work for a little bit longer but still drifts away and shuts down after a while.The OVER TEMPERATURE led is not lit so the temp seems fine. Is there maybe some short? Is it simply put TOAST for the moment??

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 07:26:49 pm
content: ANOTHER UPDATE.It does the same thing (starts to drift away in current upwards and shuts down) even without the DC LOAD engaged.My instinct tells me that its some kind of capacitor fault. It basically can not keep pissing over itself when charged or something like that like its charging but at some point overflows or something.. Any ideas?

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 09:23:32 pm
content: I am now running another power supply of 19V 3.42A (currently drawing 2.99A at 18.85V).The tester seems to run well since 10 minutes.Can it be that the other power supply of 12v 1a was below some minimum? Maybe it was IT that was toast.Also, this time around I respected the manual which said to turn on the source as the last step....It is running as I am typing and the test subject power supply is getting warm as it is supposed to. If its still drawing in an hour I will post that.Also, this load has not been running for more than three years. Can that have to do with anything? For example, the first few tries the fans were not constantly running. After a few tries, they are... even after a cool down period. (anyways I doubt it gets any hot from such small currents considering the capacity of this machine). If it is still running in an hour I deem it working for now. Next step would be to source a more powerful test subject power supply and run that for a while.Any input would be massively helpful.

author: IAmHuman
author_rank: Contributor
timestamp: August 16, 2020, 10:17:25 pm
content: Last one for tonight.It ran well for about an hour drawing 2.99A from the power supply which fluctuated between 18.84v to around 20v.It seems the electric load tester is working.If I have any issues with this machine I will post in the repair thread next time. The only mystery left for now is why the fans do not run constantly each time I turn it on. Right now, they are on every other time. Either constant on OR initial spin up and off (with a little nudge when turning the unit off)Good night!

author: Johnny10
author_rank: Frequent Contributor
timestamp: August 17, 2020, 01:29:21 am
content: Fans will only come up as needed.So far you have put an overload on your power supplies by demanding more than their rating.This unit is sophisticated in options available to protect the load.I would imagine the protection circuits kicked in to protect your power supply.I believe you will burn up your power supplies way before hurting that BEAST !Those amperage fluctuations are your load trying to keep up with the strain of maximum current demand.You have only had 60-80 watts on a device that can handle 4000 watts.How hot did the power supplies get?

author: IAmHuman
author_rank: Contributor
timestamp: August 17, 2020, 10:49:46 am
content: I couldnt try the first one for too long. (12v 1a)The next supply (19v 3.42a) was running for an hour at a load of 2.99a.It got as hot as an old laptop power supply gets under normal use. Not excessively hot nor lukewarm, somewhere in between.

author: IRFP
author_rank: Contributor
timestamp: August 17, 2020, 01:25:48 pm
content: Hello,What is your use of this charge?I make this kind of device with "Super Mosfets" but your model is dedicated to industrial use!

author: IAmHuman
author_rank: Contributor
timestamp: August 17, 2020, 02:38:10 pm
content: I adopted it 3 years ago from an engineering school. It was orphanedI dont really have any use for it.pm sent.

author: IRFP
author_rank: Contributor
timestamp: August 18, 2020, 08:18:01 am
content: Hello,Interestingly, the size and weight of the equipment is the problem!I don't have room for a rack of this size.