Hello everyone,
my electrician has finally started work, but I’m not sure if what he’s doing with the screed is really appropriate. It’s an old building from the 1960s with a floating screed about 4cm (1.5 inches) thick.
To get past the chimney, the electrician chiselled out several centimeters of the screed along the chimney wall. I think this is somewhat acceptable, but now he is filling these grooves with screed again without installing an expansion joint next to the adjacent wall. He installed NYM cable. Shouldn’t it be at least NYY? Can a Cat7 cable handle this installation method?
To get past a room entrance door, he again cut grooves in the screed and laid a cable right across the door threshold area instead of routing it around the top of the door frame. This can’t be good for the NYM cable if people keep stepping on it… I’m also worried about the movement of the screed here. The more I think about it, the less comfortable I am with having a cable running through the door threshold like that. This doesn’t seem right.
For the ceiling lights, the electrician plans to cut grooves into the screed of the floor above and drill straight down. He has already drilled and the NYM cable is currently lying on the screed without grooves. Is this type of installation within the screed acceptable, or should I urgently stop him before he causes more damage to the (thin?) screed tomorrow?
Sorry that I can only provide the photos tomorrow.
Best regards,
Tassimat
my electrician has finally started work, but I’m not sure if what he’s doing with the screed is really appropriate. It’s an old building from the 1960s with a floating screed about 4cm (1.5 inches) thick.
To get past the chimney, the electrician chiselled out several centimeters of the screed along the chimney wall. I think this is somewhat acceptable, but now he is filling these grooves with screed again without installing an expansion joint next to the adjacent wall. He installed NYM cable. Shouldn’t it be at least NYY? Can a Cat7 cable handle this installation method?
To get past a room entrance door, he again cut grooves in the screed and laid a cable right across the door threshold area instead of routing it around the top of the door frame. This can’t be good for the NYM cable if people keep stepping on it… I’m also worried about the movement of the screed here. The more I think about it, the less comfortable I am with having a cable running through the door threshold like that. This doesn’t seem right.
For the ceiling lights, the electrician plans to cut grooves into the screed of the floor above and drill straight down. He has already drilled and the NYM cable is currently lying on the screed without grooves. Is this type of installation within the screed acceptable, or should I urgently stop him before he causes more damage to the (thin?) screed tomorrow?
Sorry that I can only provide the photos tomorrow.
Best regards,
Tassimat
NYM cables are suitable for installation in screed or directly embedded in plaster. NYY cables are not necessary.
CAT cables should, of course, be installed inside a conduit.
Sheathed cables may also be laid in screed without a conduit. This method is outlined in VDE 0100-520, Table 52H under reference number 52. According to Table 9 in DIN VDE 0298-4, reference installation method C should be used to determine current-carrying capacity. However, it should be noted that saving on conduit installation leads to reduced mechanical protection. Installing cables and wires in conduit with at least classification code 2 according to DIN 50086 (VDE 0605) can be considered mechanically protected according to subsection 522.6.1. The executing professional must assess whether the mechanical protection, which is also provided by the floor, is sufficient. If sheathed cables are installed inside conduits (reference number 5A), this is associated with a reduction in current-carrying capacity.
CAT cables should, of course, be installed inside a conduit.
Sheathed cables may also be laid in screed without a conduit. This method is outlined in VDE 0100-520, Table 52H under reference number 52. According to Table 9 in DIN VDE 0298-4, reference installation method C should be used to determine current-carrying capacity. However, it should be noted that saving on conduit installation leads to reduced mechanical protection. Installing cables and wires in conduit with at least classification code 2 according to DIN 50086 (VDE 0605) can be considered mechanically protected according to subsection 522.6.1. The executing professional must assess whether the mechanical protection, which is also provided by the floor, is sufficient. If sheathed cables are installed inside conduits (reference number 5A), this is associated with a reduction in current-carrying capacity.
Wow, thank you. I didn’t expect such a detailed answer including the standard.
The mechanical strength is still my biggest concern. I would need to be able to restore the currently partially filled expansion joint in the screed.
Photos will follow shortly, I first need to attend an appointment at work.
The mechanical strength is still my biggest concern. I would need to be able to restore the currently partially filled expansion joint in the screed.
Photos will follow shortly, I first need to attend an appointment at work.
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