Worse, much worse, is when the c.t. core is ferrite (as in the YHDC SCT-013-xxx series). A tight fit there could snap the core and render the c.t. useless. So, unless the c.t. has provision to clamp onto the cable, never clamp or wedge the c.t. onto the cable.
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Very well…
Thank you again.
Jorge
Good morning (USA EST) Folks,
I just placed an order for two SCT-13-000 sensors. I will use them to fit check all circuits I want to measure (I think the only two lines that are too big for the blue CT are the main lines that feed into the main panel). If will sent picks to make sure fit is appropriate (based on your feedback 
).
I also reached out to magnelab (aim dynamics actually) to order a UCT-0300-000 and a UCT-0500-000 to do the same. I will order (I am actually thinking ordering the yhdc 200a sct023r CT as aim dynamics requires PO or email orders…) only if the blue CT does not fit / work. If the blue CT fits, I will definitely need to extend the wire…or rearrange a few things next to the panel enclosure…
Hopefully, soon after for checks I will order the equipment.
Regards,
Jorge.
Correct. The wire window in the SCT-013 CT is 13mm, but your Service Entrance Wire OD is ~16mm.
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Just got two sct013’s from OEM. Will do some verification fit checks (without power of course).
I am still waiting for the sct023r’s.
Almost there…
Regards,
Jorge.
This is the 200a yhdc CT i got: SCT023R Split Core Current Transformer Input 200A Output 50mA Black.
Specs from ebay seller:
Model：SCT023R
Rated Input(Effective value):200A
Rated output: 50mA
Turns ratio:1:4000
Accuracy: ±0.5%
Linearity: ≤0.5%
Max.samping resistance: 80Ω
Work frequency:50Hz-400Hz
Operating temperature: -30℃~+65℃
Storage temperature: -40℃~+85℃
Fire resistance:UL94-V0
Dielectric strength(50Hz 1min): 3.5KV
Weight: 105g
Jorge
You won’t have any issues there.
I have an SCT-013 on an AWG 6 wire. It fits with plenty of room to spare.
Other than the Service entrance wires, the largest wire in your load center is AWG 6.
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Excellent.
Thanks Bill.
Jorge
I am pretty sure you are right. I also want to check how the CTs fit in the box as I will need quite a few.
I have learned a lot in this thread. Feels good to move fwd in a project. Thanks for the time both.
Regards,
Jorge
Your load center is fairly well full. You might have to get creative there. 
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But if not linked circuit breakers, it still has to be a linked switch disconnecting both legs of the 240 V circuit, by virtue of the fact that it’s really a 120 - 0 - 120 V system, to assure safety.
Exactly. That’s why I added:
e.g.
Yes, but if one fuse disconnects, the remaining leg remains live. So one fuse rupturing leaves a lot of the downstream circuits still potentially dangerous.
True.
That said, the device is very common. I have one on each of two central aircon compressors
and had three of them in the house I owned in Montana. They’ve been around a long time,
i.e. I’ve seen them in houses that were built in the 1920s as well as present day construction.
As Litigious as the US is, they would’ve been taken out of service long ago if anyone thought
there was a need to do so.
I’m not saying there isn’t an issue when only one fuse blows. That’s a given.