mani Iy604 self contained indigo
Brief history of the unit. Couple of months back at a local university an Ice machine was installed. Electrical storm popped up and fried the board on this unit. 0 ohms between L1 and L2. Tech support said change out the board under warranty. Head honco onsite told his maintenance guys to install some sort of surge protection to prevent this from happening again.
Two weeks later, another storm and another board fried. This time they ate the cost of the board and replacement and installed a supco scm150 surge arrester on the panel box. New board comes in and installed and everybody is happy.
Last Thursday another storm came by poof! Another board. I went out there today already having an idea what it was. Isolated the board, replaced the fuse, restored power and same thing, the board is gone. I spoke with Bert at mani tech support, great guy btw, and he said that only a high voltage spike can fry a board. If a component fails, dump valve, inlet valve, hgv solonoid valve shorts out that the fuse will blow and thats it, The board should not be damaged in anyway. He did warranty that board too.
I checked the wiring of the supco scm150 and it is wired in parallel on the outlet of the 20 amp breaker going to the unit. The ground it wired to the bus bar. Voltage at the outlet is 242 volts with each leg within a tenth of a volt to each other. From what I read on supco's pdf file is that this surge arrester works by shunting power to ground in the event of a power surge.
I spoke to the head maintenance guy to have his electrician look at the panel box again and to recheck the wiring of the surge arrester to verify that it is wired correctly and to verify that the ground was hooked up properly. I was offsite at the time and unable to check myself.
Has anyone come across this problem and how were you able to correctly address the situation so it would not happen again.
Thanks again for any input.
Could there be an issue out at the transformer on the pole? Maybe the blame is on the power provider, though they'll never admit it.
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one way or the other power is the problem. From what I can tell Power surges are a big problem at Methodist University. The funny thing is, the last IM they had in that shed never had a single issue with fried boards. I understand that technology brings problems at times. But I don't want that to be my excuse.
I know that mani isn't going to keep replacing boards till the one year is up and then they are on their own. could it be the quality of the surge arrester? The only way you know it is working is the magical green led. Should I suggest a different brand?
I have had to have electricians move taps on the transformer after doing a electrical input mapping over a period of a couple of days. what we found was Elec comp. would jack up voltage as demand rose after second shift shut down on the block voltage was way above what units could tollerate once they move taps unit ran fine.
If I'm not mistaken those supco scm 150 will only protect electro mechanical
But will not protect control board or any electronics
Actually the warranty is 3 years. But your right about replacing it over and over again for electrical surges.
The postings on this site are my own and don't necessarily represent The Manitowoc Company's positions, strategies, or opinions.
Had another call out there today for a walk in freezer and I was able to speak to the Head Maintenance guy.
He said that when that building was put it, they ran a line out from the main building. L1, L2, and a ground wire. His electrician installed a dedicated ground rod just for that building that was wired into the panel box.
We both speculated that with the length of the run it may have interfered with the surge arrester being able to function properly. The pdf said 25 ohms was the max for their product. He mentioned that they also have some installed for the puter room and those spec out at 5 ohms to perform properly. I suggested he may want to install that since it is protecting an electronic board instead of a motor.
Thank you for the input gents.