What is the max Zs on a 60947 2 Mccb?
According to Square D, a 250amp MCCB has a max Zs of 0.09. The installation i am working on has a Ze of 0.11….See Also:
| Technical discussion forums | |
|---|---|
| · | Other and general engineering discussions |
| Archived categories |
What is the maximum ZS permitted by bs7671?
The 1.37 ohms value is the 100% max Zs value which should be recorded on the test certificate.
How does Mccb calculate max Zs?
Max Zs for 60974-2 MCCB Please ensure the tables are to the current version of the wiring regulations and factor in the Cmin factor @ 230V. The Cmin factor is 230 x 0.95 = 218.5 volts, therefore to calculate Zs: 230 x 0.95 = 218.5, 218.5 / la = Zs.
Should ZS be higher than r1 r2?
So with power on testing for Zs at the spur with the highest R1+R2 and we get Zs = 0.67 Ohm. Zs=Ze+(R1+R2) well not in this case….See Also:
| Technical discussion forums | |
|---|---|
| · | Wiring and the regulations |
| · | Other and general engineering discussions |
| Archived categories |
How do you calculate ZS from r1 R2?
To measure Zs do just that go to the highest point of R1+R2 on that circuit and carry out a live test. Record your result. 2. Calculate Zs by Zs=Ze+(R1+R2).
Is it OK to calculate Zs?
It seems that nowadays it is acceptable across the board to calculate Zs. When I used to do a lot of testing, the contractor I worked for insisted on measured readings. That was the company line and therefore that is how I used to work. At that time a calculated Zs was seen as “lazy”, so that is my mindset still.
Should R1 R2 be lower than Zs?
Zs=Ze+(R1+R2) well not in this case. Just not come across such a difference before that Zs has been so much lower than Ze+(R1+R2)….See Also:
| Technical discussion forums | |
|---|---|
| · | Wiring and the regulations |
| · | Other and general engineering discussions |
| Archived categories |
What are the maximum ZS tables for 60947-2 MCCB’s?
The maximum Zs tables and charts for BS EN 60947-2 MCCB’s varies between manufactures and specific to the MCCB part number, then again depending on the settings of the actual MCCB device. Due to the many variables there isn’t a quick Zs calculation for 60947-2 MCCB (moulded case circuit breaker) or ACB (air circuit breaker) protection devices.
What are the maximum permitted ZS values for 60947-2 protective devices?
The maximum permitted Zs values for 60947-2 protective devices vary between different manufacturers, for instance 60947-2 Merlin Gerin Zs values are different to 60974-2 Eaton Zs values and 60947-2 Square D max Zs values are different to 60947-2 Dorman Smith and ABB max Zs values for example.
Is there a BS7671 value chart out there?
There are no all encompassing figures such as the BS7671 info that exists for other devices. You make a list and call them once or find a website with the values listed, without you giving us a brand we can’t really guide you any better as their are many makes and models and not all have readily available charts.