FLYGT FLS Installatie- en toepassingshandleiding - Pagina 6

Blader online of download pdf Installatie- en toepassingshandleiding voor {categorie_naam} FLYGT FLS. FLYGT FLS 12 pagina's. Leakage detectors

Checking the sensor circuit and fault finding

Connect a multimeter in series with the sensors or

use the ITT Flygt sensortester "ST-1" (FD part no.

10-581700) to measure the current in the sensor

circuit. See figures below.

"ST-1" is not yet prepared to handle the new sensor

FLS10.

The figures on page 2 is used as reference to deter-

mine the status of the sensors (sensor connections).

Circuits with CLS require some extra consideration.

Connected with wrong polarity the CLS draws a zero

current. The CLS can then be considered not connec-

ted.

General procedure to check the status of the sensors

1. Close the sensor circuit by connecting the multi-

meter test leads according to figure above or on

next page.

2. From the moment contact is made, observe the

sensor current for at least 5 seconds (to await a

possible CLS alarm current).

3. Switch polarity of the sensor leads (5, 7) and repeat

steps 1 and 2.

4. Identify the actual sensor circuit with the help of the

first page figure and analyse the sensors' status.

5. In case circuit (4) is used: By using the wrong po-

larity and delay properties of the CLS, it is possible

to conclude if a leakage alarm is attributed to the

CLS or FLS.

6. To ensure that the polarity is right after the mea-

surement, restore the connection resulting in the

largest current.

Wrong polarity results in 0 mA for circuit (3). Circuit (4)

is reduced to the same as circuit (1).

As opposed to the FLS and FLS10, the CLS has a

built-in alarm delay of 5 seconds.

Since the MiniCASII has only one leakage indication

lamp, an alarm from the CLS or the FLS looks the

same.

For circuit (4), this means that a leakage alarm can

not be attributed to either of the two sensors just by

looking at the MiniCASII. To make out the tripping

sensor without lifting the pump, a measurement of the

sensor current is necessary.