Contents

- Can you work out r1 r2 from Zs?
- How do you calculate Zs?
- Should R1 R2 be lower than Zs?
- How do you measure Zs at DB?
- What is the 80% ZS rule?
- What is R1 R2?
- Why do you divide R1 R2 by 4?
- What is difference between Ze and Zs?
- Is it OK to calculate Zs?
- What does a ZS test prove?
- What is R1 and R2 in math?
- How do you find current with R1 and R2?
- How is ze value calculated?
- What code is a high Zs reading?
- How do you measure ZS on a ring circuit?
- What is the maximum Zs for an RCBO?
- Is ZDB the same as Ze?
- What does R1 and R2 prove?
- How do you calculate parallel circuits?

## Can you work out r1 r2 from Zs?

No, because it’s measured by the parallel paths that are disconnected. You can get a parallel path through the pipework if you do an R1+R2 on a boiler circuit. If you don’t connect the cPC both ends, it will be useless.

## How do you calculate Zs?

It is permissible to derive the loop impedance of a circuit by using the following formula, if reliable measured values are available.

## Should R1 R2 be lower than Zs?

This is not the case with Zs. It wasn’t until Zs was so much lower that you could see the difference.

## How do you measure Zs at DB?

Zs is the total obstruction of the circuit. The origin of the supply can be found in one single Ze. The board that is fed by the sub main will have a Zs value that is roughly the same as R1 and R2. The Zs are measured at the incomming terminal of the sub board.

## What is the 80% ZS rule?

The 80% rule of thumb is only meant to apply to a test result. You have to make sure the tested value doesn’t go over 80%.

## What is R1 R2?

Each outlet on a circuit has its resistance measured back to the source. On a radial circuit, the cable resistance gets higher the further away you get from the source.

## Why do you divide R1 R2 by 4?

Dave, you are confusing two different tests, the one that is done to calculate R1+R2 is done by measuring the resistance of the cPC end to end, then dividing by 4 to give R2 repeat for the phase conductor to give R1, and the other is done by

## What is difference between Ze and Zs?

The total impedance of the complete circuit is known as Zs. The conductor is R1. Our circuit is resistant to R2.

## Is it OK to calculate Zs?

It seems like it’s acceptable to calculate Zs across the board. I used to work for a contractor that insisted on measured readings when I was doing a lot of testing. I used to work that way because the company line was what it was. At that time a calculated Zs was seen as lazy and I still think that way.

## What does a ZS test prove?

The Zs test is not to prove an earth connection, but to prove that the CPD will operate within the time required by BS 7661. It is notmpling equipment that is being tested.

## What is R1 and R2 in math?

The Department of Mathematics & Statistics offers a number of courses that meet the R1 requirement for graduation.

## How do you find current with R1 and R2?

The Ohm’s law is used to find the current across the resistors. I1+I2 is the total current in the circuit. Ohm’s law can be used to find total resistance and see if our total current is correct.

## How is ze value calculated?

R1 and R2 are the same number. If you don’t have to take insulation resistance or rcd time, you can do testing.

## What code is a high Zs reading?

The high Zs are shown in the latest PIR. If a Zs value is high, you need to know if it’s due to a fault, a circuit condition, or both. The appropriate course of action can be decided by you.

## How do you measure ZS on a ring circuit?

To find the zs of a ring circuit, you need to cross connect at the origin of the ring, then connect the incoming phase to the outgoing cPC, and measure between the two at all of the sockets.

## What is the maximum Zs for an RCBO?

Table 41.5 shows the max Zs that are L-E loop. For 32A type C RCBO, the L-N loop should not be more than 0.72 ohms.

## Is ZDB the same as Ze?

The Comlec Screwfix Select can be used. The Ze and Zdb are essentially the same when a database is fed from an installation. The Zdb would be slightly different if there was a switch fuse in the database.

## What does R1 and R2 prove?

The phase and earth connections are sound according to the R1+R2 test. Its merits are that it is a very low current test. If the connections are suspect and there is a layer of oxide over them, you’ll get a high resistance.

## How do you calculate parallel circuits?

There is a total current in a parallel circuit. If more resistances are connected in parallel, the circuit resistance will be reduced.