Instruction Manual
  <1. Overview>
1-23
IM 11B08A01-01E
Protection system
Control unit
Oven unit 1
Oven unit 2
Oven unit 3
Stanchion*1
Flow 
control 
section
Warning plate
GC-HMI (touch panel) *2
Electronics 
section
EPC box *3
LSV (liquid 
sample valve) *1
Pressure 
control 
section *1
Isothermal 
oven section
Data plate
*1  A stanchion is mounted on the self-standing type.
  External sampling systems can be connected as needed.
*2  Depending on the specifi cations.
Figure 1.5  Structure and components of Type 3
1.10.2  Components and their Functions
(1) Protection  System
The protection system is a fl ameproof enclosure and contains the protection circuit in the 
pressurized enclosure. The Y-purging specifi cation (FM) does not use this system.
This device contains the power relay, pressure switch, timer, relay, illuminance sensor, and 
override switch.
The device monitors the internal pressures of the pressurized enclosures (the electronic section 
of the control unit and oven units 1 to 3, the large isothermal oven or the isothermal oven) while 
the power is on, and if any of them indicates lower than 392 ± 20 Pa, the protection system will 
automatically turn off the power.
This automatic power-off can be disabled by a function called “overriding.” To enable this 
function, open the cover of the protection system and press the override switch while the 
illuminance sensor is detecting light of 100 lx or more. When the illuminance becomes lower than 
10 lx, the function becomes invalid, and the automatic power-off prevails. The override function 
allows operators to open the door of the protection system while the power is on. However, 
make sure the ambient atmosphere is not hazardous before opening the door for repairs or other 
purposes.
Refer to Chapter 2 for details of checking the status display of the protection system and override 
function.
*  Guideline for illuminance and brightness
    In an offi ce with fl uorescent lights: 400 to 500 lx
    Under a street lamp: 50 to 100 lx
    Candlelight (at a distance of 20 cm): 10 to 15 lx 
  Ordinance on Industrial Safety and Health, Article 604
    For precision work: 300 lx or more
    For ordinary work: 150 lx or more
    For rough work: 70 lx or more
2nd Edition : May 11, 2012-00
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