Cable Testers

A recent new facility is having a lot of problems with wiring, Wifi APs going offline, and high latency. I suspect the wiring as it’s all new and some patch cables were created onsite. A new server only connected at 100mbps and when the patch cable was replace with a new, store-bought cable the connection increased to 1000mbps. I suspect their “Electrician” does not know enough about ethernet cabling, creates patch cables that have split-pair condition (3+4,5+6 instead of the correct 3+6,4+5) and uses a cheap cable tester that can’t test for split pairs.

Here are the least expensive testers i can find that test for split pair condition. Note I haven’t received the unit yet to test as it was delivered directly to the site.

Southwire M550: $64cad
I’m going to recommend this unit as it can give diagnostic information as to WHY the cable doesn’t pass.
Pros:
-1 button operation, easy to read pass/fail condition
-also tests Coax
-remote unit stored inside the tester so it doesn’t get lost
-shows the correct wiring of pairs in 2 places on the unit
Cons:
-combinations of LEDs requires looking up in the manual, so don’t loose the manual, some of the common LED combinations could be printed on the rear of the unit

Not an affiliate link, I don’t get any reimbursement for recommending this product
https://www.amazon.ca/Southwire-Tools-Equipment-M550-Continuity/dp/B01ADWQ94A/ref=sr_1_8?dchild=1&keywords=network+cable+tester+%22split+pair%22&qid=1621002572&sr=8-8

Alternate Choice:

Klien Tools: $50cad
This unit wins on price BUT if there is a problem there is NO diagnostic information to guide you in re-wiring or otherwise fixing the problem. it only shows an LED that says Miswire, not super useful.
Pros:
-inexpensive
-easy 1 button operation, easy for an electrician to determine pass/fail
Cons:
-no information beyond pass/fail to guide the operator in re-wiring / fixing the problem

same disclaimer
https://www.amazon.ca/VDV526100-Network-Tester-Explorer-Remote/dp/B07RT1J9MB/ref=pd_vtp_3?pd_rd_w=yzjuR&pf_rd_p=42ad2502-0d93-40f9-bcf4-49a0657bb461&pf_rd_r=7BSV73W6TCD0TD9ZGC63&pd_rd_r=3a458ae3-bc36-40d4-8a38-64432f6255f3&pd_rd_wg=NOqY5&pd_rd_i=B07RT1J9MB&th=1

There are lots of Sub $10 testers that only test for continuity, I don’t recommend these as they can give a false sense of security. In our case the home-made patch cables passed the continuity tests but had split pairs that caused a bunch of network strangeness, low connectivity speeds and some devices on longer runs that wouldn’t connect at all.

There are more expensive units that can tell the distance to a cable break. I have used VERY expensive units like the FLUKE OptiView (a tablet with built-in tester!), they are nice units but unless you are wiring full-time, I’ll recommend you RENT a more expensive unit when required. Knowing WHERE a conductor is broken doesn’t make replacing the cable cheaper.