Utrecht
- Page 10 -
Ref. 001
b) Alternating form (starting phase 180°)
Figure 2: Alternating fault current.
Structure
The RCT-S is an electronic microprocessor controlled instrument intended for the execution of all
tests concerning different protective switches with differential current protection (with or without
switch-off delay) Select the test by means of the rotary switch. The user is able to prescribe the desired
measuring
method
now
RCD types which can be tested by RCT-S:
1.
The
sensitivity
according to the form of the fault current
-
type
AC.
2.
The
disconnection
delay
- without delay (standard type);
- with delay (selective type).
3. The rated values of the fault currents
- 10 mA; 30 mA; 100 mA; 300 mA; 500 mA.
Connecting
The instrument is powered by four alkaline batteries (4 x 1,5 V IEC). The tester is provided with a on/off
switch and can, after powering up the instrument, be used at once. The test cord or the RS232 cable (data
transfer cable) are connected at the upper side of the tester.
Measuring
Each test has it’s specific circuit diagram which is given in the attachments.
The
following
measurements can be executed by the instrument:
1. The contact voltage (Vc) at the current of I
Δ
N
(ordinary type) or at the current of 2I
Δ
N
(selective
type) without tripping
2. The tripping time (t) at the current of I
Δ
N,
2I
Δ
N,
5I
Δ
N
3. The trip out current (I
Δ
) and the tripping time (t) at the trip out current (I
Δ
)
4. The mains voltage between the phase and the protective earth terminals
