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Your cart is empty.The product type is Jameco Valuepro GRP-1200 Transformer, Isolation, Benchtop, 120 VAC, 4A, 60Hz, 450VA, 8.86" L x 6.10" W x 4.33" H. Made in China and manufactured by Jameco Valuepro.
terry01
Reviewed in the United States on June 10, 2021
Note for full isolation use a 3 to 2 prong adapter as the grounds are common between the line voltage and the isolated ac side.
David Hogston
Reviewed in the United States on August 29, 2020
Does what it is supposed to do. Only complaint is the screws holding the transformer to the bottom of the cabinet. 3 were loose before the unit was taken out of the plastic bag wrapping it. Good thing it was wrapped in the bag as it kept the 4th screw that already had fallen out from becoming lost. The nut & washer for the screw were rattling around inside of the cabinet. Had to put the screw back in and tighten the other 3 up before even plugging the unit in. Took longer to write this review than it did to fix the unit.
A.Greene
Reviewed in the United States on July 10, 2020
I took other reviewers advice and looked inside for damage. Mine only had a few solder problems albeit ground wires. So glad I I looked. shipping damage is also an issue. my cover is bent on one corner and transformer was loose but not completely.Pros; seems well built as far as metal case and parts used. Works as described.Cons; poor soldering. The ground terminal at the direct AC outlets was not connected as the solder joints had failed. The wire from the chassis ground was still soldered to the thin uninsulated wire that ran across all 4 outlet ground terminals. brings me to my next point. All 4 ground terminals are connected and attached to the chassis ground. As is the ground wire coming in from the power cord. So as other reviewers have stated this is NOT TRULY ISOLATING transformer. Mine did however have the output neutral wire isolated from the incoming neutral. so all I had to do was remove the isolation side grounds back to chassis. The assumption is that this is not an off the shelf plug and play device. Careful examination required by qualified person.
Dennie M.
Reviewed in the United States on November 16, 2020
Be aware that the isolation side of the transformer, that is the left two receptacles in back of the front panel are grounded. You can see the common bare ground wire tying all 4 receptacles (2 isolated, 2 direct to main) together. The 2 isolated receptacles (left) would need to be disconnected from ground for true isolation (ie, oscilloscope protection from DUT).
GJ
Reviewed in the United States on October 24, 2020
The isolation transformer arrived as described by previous reviewers, transformer rattling inside box, screws loose in plastic bag, fortunately the box was OK. Had to bend back bent mounting tabs on transformer and put star washers on mounting bolts. Grounding bolt was as described, not making contact with the case, scratched paint away from case and installed star washers. The cord is undersized #18 with a 15 amp fuse in the 14A labeled holder....really? Max rating on #18 cord is 7 or 10A Depending on your choice of website. The safety ground wire between the grounds on the sockets looks pretty small to short a 15A load. I am going to use smaller fuses, use a larger safety ground wire between sockets a heavier cord and plug and add a switch to turn off the AC power to all the sockets. Looks like it might be useable then. This really should be advertised as a kit!
Carl at CTC
Reviewed in the United States on February 13, 2019
The Isolation Transformer seems to be functional after my preliminary test with light bulbs and a DVM.It also is compact and nice looking.I took off 1 star because they did not use lock washers on the nuts holding the transformer to the case inside.My unit was dented and all the transformer screws and nuts were loose and about to fall out. Also, three of the sheet metal screws that hold the outer cover on the case were stripped. I was not about to return it and have to wait another 85 days or more to get another one, so I tightened the transformer screws and straightened the bent cover myself. Another thing is that it does not match the circuit diagram shown on the Jameco website. Jameco shows no wires on the any of the terminals of the output ground sockets, but this transformer has all the grounds on the output tied together and grounded to the case like the input ground. When I hook a light bulb between Hot and ground the bulb does not light, so there is isolation between hot and ground, but I'm still nervous that the grounds are tied together and to the case. The transformer makes a clunk sound when first powered on, even with no load. I guess that is because there is no vibration isolation between the transformer and the case.All in all, I like it and am going to keep it.
MasterTacoChief
Reviewed in the United States on August 25, 2018
Great isolation transformer with on/off switch. Important things to note:- Safety GND is connected to ALL outlets. You must bypass this for true isolated output.- The direct outlets are not switched, so they are not isolated and always on. Useful for plugging in other equipment (scope, etc.).
Frank
Reviewed in the United States on April 2, 2017
This is a simple isolation transformer that seems to work well. There are two sockets that are isolated and two sockets that are not. They are clearly marked. I checked the voltage output on the isolated sockets and they are within 0.15 volts of the input under no load at 120 v nominal. There is a very slight and barely audible transformer hum at zero load. However, this should not be an issue for most situations. Be aware however, that the ground lugs on the isolation sockets ARE connected to the ground lugs on the non-isolated sockets. Thus it is not a truly isolated transformer for tech bench purposes. This transformer will not "float" your oscilloscope.My only complaint is that the transformer's case was slightly bent and paint damaged on two of the four corners. It was not due to shipping as it was double boxed and did not have obvious shipping damage. It must have been that way from the factory - disappointing cosmetic quality.
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