SPD location and configuration

[Electromatic]

I'm looking to install some surge protection for a quasi-industrial site with several CNC-type machines, robots, etc. The service is 480V - Y. There is (as required) the neutral at the outside service disconnect. From there, only the three phase conductors and ground go several hundred feet inside the building to the breaker panel. Would it be better to install a SPD at the service disconnect and use a 4-wire device or at the inside panel with only 3 wires(+gnd)?
It seems like outside would have a better path to divert surges, but I believe it's typically recommended to install SPDs closer to the equipment it's intended to protect.
Also, if I put the SPD at the panel with no neutral, would it matter that the device is labeled as being for a delta system? It seems like most 3-wire devices are so labeled (being a more common occurrence).
Finally, the service disconnect is a fused switch and the breaker panel is full. Though I know it's not kosher, I'm tempted to 'double-tap' the SPD wires onto a breaker or the switch lugs. Are there better/more approved methods?

Thanks as always.

 

[Jraef]

Depends on the “Type” of SPD you are talking about. A Type 1 goes at the service entrance and protects the entire facility. A Type 2 goes at the distribution board /panel board that feeds an sub-area of the facility that you want protected, a Type 3 goes right at the load connection point. In general, you want the Type 1 to bear the brunt of the burden of protecting without failing, so they are the most robust and consequently, the most expensive. Type 2 are less expensive, but kind of rely on the impedance of the service circuit ahead of it (or a Type 1 SPD) to dampen the peak of any surge or spike. Type 3 are the dirt cheapiest and are considered all but useless in most readily available retail formats, but industrial grade are fine, however SHOUKD be used in conjunction with Type 1 and/or 2 to be most effective.

 

[tom baker]

Depends on the “Type” of SPD you are talking about. A Type 1 goes at the service entrance and protects the entire facility. A Type 2 goes at the distribution board /panel board that feeds an sub-area of the facility that you want protected, a Type 3 goes right at the load connection point. In general, you want the Type 1 to bear the brunt of the burden of protecting without failing, so they are the most robust and consequently, the most expensive. Type 2 are less expensive, but kind of rely on the impedance of the service circuit ahead of it (or a Type 1 SPD) to dampen the peak of any surge or spike. Type 3 are the dirt cheapiest and are considered all but useless in most readily available retail formats, but industrial grade are fine, however SHOUKD be used in conjunction with Type 1 and/or 2 to be most effective.

Exactly. Type 1 at the service and type 2 at feeder panels. I like the Leviton 52,000 series for services and then a 42,000 or 32,000 at feeder panels.
As for SPDs, “you get what you pay for and more is better” Mike Holt.
After I started installing spds at services and panels, my electronics equipment no longer had power supply failures.

 

[Electromatic]

I understand the difference of Type 1 & 2 with regards to location. (Though, TBH, I'm not sure if the actual difference is a listing thing or the broad characteristics of each type.) I'm more interested in opinions on which location would theoretically be better if you were to only install one device. I've asked the customer for a ballpark budget as these devices vary hugely in price--if I can fit both locations into their budget, all the better.
Any thoughts with a 'delta'-labeled device being used on what is actually a wye with no neutral? Or connection methods when there are no extra breaker/lug spaces available?

 

[jim dungar]

Any thoughts with a 'delta'-labeled device being used on what is actually a wye with no neutral? Or connection methods when there are no extra breaker/lug spaces available?

Do not use a Wye device if you do not have a place to terminate the neutral lead.

A service rated device is expected to handle power line surges, like from nearby lightning, so they have relatively high operating levels. They are not always effective at protecting sensitive equipment so we have branch/feeder protection with lower operating levels but also with less ability to handle frequent power large surges which may be found in lightning prone areas like Florida.

For sensitive equipment even lower operating points are needed, so we have point of use devices which frequently do not survive when asked to take on the role of a service or feeder device.

 

[tom baker]

Leviton has delta and wye units. The 52,000 series has replaceable modules, it also can be use as a feed thru, ie land wires from ocpd, then is second lug to continue to load
And remember the Mike Holt quote