Operation
Ex p control unit
Motor Purge Controller
Page 56 of 96
01-37A2-7D0003_Operating instructions_MPC_20210923_0_en.docx
Rev. 0
7.13.1.2
Delay
The “Delay” setting can be used to store a delay time which delays the shutdown
if the pressure falls below the minimum value.
The set delay time means that if the pressure falls below the minimum pressure
p1, the immediate switch-off is delayed by the delay time. If the pressure rises
above the minimum pressure again during the delay time, no shutdown occurs.
7.13.1.3
Purging programmes
DANGER
DEATH OR SERIOUS PERSONAL INJURY DUE TO THE USE OF AN INCORRECT
PURGING PROGRAM
Danger to life due to unsafe condition.
Use only the purging programmes intended for the application.
The release relay K2 switches depending on the set configuration.
The following purging programmes with functions are available for purging a
pressurised motor with the Motor Purge Controller.
Purging programmes for gas application:
Progra
mm
e
A
p
p
lic
a
ti
o
n
Functions
Purging
phase
Purging time
starts when p3 is
exceeded
Purging time
stops when p5
has been reached
Ex p active
after
Ex p
inactive
after
Ex_p_1
Gas
Yes
Yes
Yes
purging
time has
elapsed
po < p1
po > p4
Ex_p_2
Gas
Yes
Yes
Yes
purging
time has
elapsed
po < p1
Ex_p_4
Gas
Yes
Yes
No
purging
time has
elapsed
po < p1
po > p4
Ex_p_5
Gas
Yes
Yes
No
purging
time has
elapsed
po < p1
7.13.1.4
Purging time
It is assumed below that the amount of purge gas is determined as a function of
the housing volume of the pressurised enclosure (volume-dependent purging
time).
The flow rate of purge gas at the outlet of the pressurised enclosure is used to
calculate the purge time.
Select orifice size based on the type
Orifice
Diameter [mm]
MPV
8
50
Type: 17-51P3-3803; mpv 2
9
100
Type: 17-51P3-3903; mpv 3
