I have a 551B Ksu id like to hook up in my work shop; I have it wired and on line 1, I can put the phone on hold, interrupter starts and lights flash. On line 2 when I push hold, the lamp just shuts off and the call drops. I have swapped the cards; that doesnt appear to be the issue.

On incoming calls on either card, the interrupter does not start, lamps dont blink and phones dont ring.

551B ksu with internal power supply and separate ringing supply.

Any help is much appreciated, I am sure there is something easy I am overlooking.

The no-hold condition on line 2 sounds like the card is bad, but since you swapped them and the trouble remains, I would check the wiring of the second line. Before you check the station wiring, here's a quick test that you can use to simulate a hold condition: take two metallic tools, such as two screwdrivers, and do the following in this order: short the T&R terminals of the line at the KSU output block. Then, while that short is there, short the A & A1 terminals at the same block. The lamp should light at the phone. Now remove the short on the A & A1 terminals while keeping the short on the T & R. The lamp should change to wink, and the interrupter should begin to operate. This test eliminates any wiring issues outside the KSU, and tests the KTU by itself. If this test results in a good hold condition, then the trouble is in the wiring or the telephone set. is the set wired for 1A2 or is it possible it was once converted to 1A? Do you have another tel set you can use temporarily? Do you have more than one tel set on the system?

As far as the incoming ring not operating the interrupter, we need to know what brand and issue of line cards you are using. (Some cards will respond to metallic ringing (across T&R) and some will only respond to grounded ringing.) That will help us figure out the ringing problem. Until we know that, consider this: Have you grounded the KSU to an earth connection? The easiest way to test if this is the problem is to run a piece of cross-connection wire from the ground screws at the top of the 66 block in the KSU to the center screw of a convenient electrical outlet. Do this and ring into the lines again.

Arthur is, as always, on the $.

Also, do you have only 1 tel set? If you have more than one, does the (line 2 hold) problem exist on both sets?

WH8428, follow up and let us know.

Sam

Some of the later versions of WE 400 cards had a weird symptom: If you picked up a line and immediately tried to place the line on hold, the call would drop. The card needed a few seconds connected to the T & R before it would hold. I believe that the 400G or 400H cards did this. It was most unsettling for an installer back in those days, not knowing that the card operated that way by (poor) design.

That's odd, Arthur. I'm running my FIOS lines with 400H & G cards. I was using SanBar 4000F's but was having problems with ringing. I started cycling cards in and out and the later WECOs have worked fine.....

Sam

No dice on either line now, so whatever the problem is its intermittent. The interrupter isn't starting on incoming ring either. I will post a pic of the wiring shortly.

I do have multiple 1a2 phones and cards; all have the same results.

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As always you guys were on the money. I grounded the KSU properly and the interrupter starts on incoming ring and everything works properly.

Thanks for the help

Arthur, I believe it was the 400E that had the problem

Glad to hear that everything worked out.

Sam

How did grounding the KSU fix the intermittent no-hold problem?

I was just axin myself the same question, Arthur. I will agree that the early 400H cards had a mind of their own, but I never heard of the absence of a chassis ground causing a hold issue. The 400H, Issue 2 series seemed to overcome just about all of the glitches, shortly before they were sent out to pasture.

Nah, that was the WECO 400H, Issue 1. Those things were completely unpredictable. I don't see any of them in the OP's pictures though.

400E was of ITT manufacture and they were bullet proof. Bell even started using them in Washington, DC instead of WE400H ones due to the huge amount of federal government 1A2 at the time. They got tired of chasing their tails.

Up here in Seinfeld Country, we were issued SanBar 4000F cards made in Mexico. They, too, were bulletproof, and even had that innovative red LED to indicate busy. That saved time and labor over the old method of identifying one 400D card in a Parker rack of 130 slots -- that is, by asking the subscriber to flash the SWHK until we could determine which KTU was clicking.

There was a Western Electric 400E line card. An article entitled"Advances in the 1A2 Key Telephone System", in the October 1970 Bell Laboratories Record, has a photo of the Western Electric 400D and the Western Electric 400E side by side.They had reduced the number of components from 41 to 17. This was done by replacing the transistors and all the components on the small secondary circuit board with an integrated circuit chip. It must not have worked out because in the early 70's the BSP for the 400 series noted the 400E Manufacture Discontinued.

Very true about the WE400E. That one came and went in no time, in fact I'm not sure if they ever went out into full distribution.

Arthur, C&P Telephone here was also using Brand/Rex (Teltronics) LC-400E cards and they got a lot of attention. The circuit boards were blue, the handle was white and the manufacturer's label was quite an eye catcher. They were the functional equivalent of ITT's 400E, but they were better-looking.

I have a couple of the LC-400 cars, New in the Box.

I have no idea where I got them from. None.

Did they do anything special?

I'll have to look.

Sam

Not that I recall, Sam. They were just another player in the equipment game pre-divestiture when RBOCs could buy their hardware from sources other than Western Electric (ATTIS) and save some money.

Thanks, Ed. If I remember (a BIG if), next time I see them/think of them I'll look them over.

Sam

"How did grounding the KSU fix the intermittent no-hold problem?" he asked, not expecting to get a reply.

One of these days I'm gonna learn and not answer any damned questions. Then all the 1A2 wannabe's can go find their answers somewhere else. I'm only an old worn-out expert in one narrow, useless, obsolete area of a vanishing industry, but I still would like to get some respect.

You're right bill I once had a "tech" install a new line , that left a note saying my service was on the "purple gray wires" of course after 30 years I felt I could figure this out.

From the manual. Maybe his outlet wasn't grounded?

3.14 Any installation of the 550/551-type KSU should be grounded and protected in accordance with the requirements in Section 518-010-105. The frame of the KSU power unit is grounded through the third, or "green," wire of its power cord. The local or circuit ground of the power unit, which is the positive side of the de output, should be connected to the same ground as the system protector. Do not connect circuit ground and frame ground together.
3.15 The 550/551C KSU has an external grounding terminal, labeled LOC GRD, on the front of the backboard above the interrupter. It is wired internally to the power unit ground circuit at the G± terminal of the connecting block. Connect this terminal to protector ground with a 14-gauge wire brought through one of the cable clamps below the connecting block. On 550/551A and B KSUs (MD), a multiple-post grounding terminal is located on the top of the connecting block.
BSP

No, grounding never had anything to do with the proper functioning of 1A2 equipment except for CO ringing, which was dependent upon the card(s)used. The hold function was accomplished through a careful balance of the A Lead and the line's loop voltage/current. If all of those were not within specification, then anything could happen, or not.

Thanks Ed I haven't touched 1A2 in a long time and when I did in the '80's it was primarily ITT and we always cold water grounded them. Never had many issues with them either except for maybe hung up 401a relays.

John: That's why WE's 551C was designed. It overcame many of those grounding issues, primarily because they realized that grounded ringing was becoming a thing of the past. Since the 400G KTUs came out around the same time, they thought they had it all licked. Or so they thought......