Yokogawa In-Situ Gas Analyzer TDLS200 - Manual (Page 22)

4-2 4-3
IM 11Y01B01-01E-A 6th Edition :Feb 13, 2013-00
<4. ANALYZER COMPONENTS>
4.2 Main Electronics Housing
Enclosure
Die cast copper free aluminum grade AL Si 12 alloy (A413.0) with a powder coat exterior finish. The copper free
aluminum alloy is particularly resistant to salt atmospheres, sulfur gases and galvanic corrosion.
An externally hinged door opening to the left incorporates a weather tight gasket seal and four captive fastening
screws (stainless steel). The external dimensions are approx 16” W x 12” H x 7”
D (400mm x 300mm x 180mm).
The environmental protection rating is considered IP65 (EN 60529) or NEMA 4X.
Cable entries are located on the bottom face of the enclosure. They are typically ¾” Myers hubs that have ¾”
NPT female threads. Each has a ground lug to facilitate the grounding of cable shields to the analyzer chassis.
When an analyzer has been supplied with the optional Mini Display (4x20 VFD), the normally blank
(blind) door has a different configuration. The center of the door has a cut-out measuring approx 3”
W x 1” H (75mm x 25mm). A clear laminated safety glass window is mounted to the inside of the door with stain-
less steel fasteners and a weather tight gasket. This allows for external viewing of the actual VFD display without
opening the door.
When an analyzer has been supplied with the optional integral 6.5” display and keypad, then the normally blank
(blind) door has a different configuration. The left hand side of the door has a cutout measuring
approx 5” W x 4” H (130mm x 100mm). A clear laminated safety glass window is mounted to the inside of the
door with stainless steel fasteners and a weather tight gasket. This allows for external viewing of the actual
display without opening the door. The right hand side of the door accommodates a keypad (30 keys, stainless
steel) which is also operated externally without opening the door.
Backplane Circuit Board
Large (approx. 10” H x 15” W) printed circuit board that mounts inside the enclosure. The board has
several integral circuits and several connectors to accommodate various plug-in boards. The board is
designed such that any field terminations are located along the lower edge of the board via pluggable
terminal blocks for customer or field cable interface.
All components and devices on the board are designed for extended temperature (-20 to +80ºC) and low drift
operation.
The Backplane Circuit Board contains the following integrated circuits:
• DC Power Input
• DC Power Distribution
• Watchdog Circuit
• Display Backlight Power Interrupt
• Alarm Relays
• Remote Calibration Initiation
• Calibration Valve Driver Relays
• Laser Temperature and Current Control
• Board temperature
DC Power Input
There are four pluggable screw terminals located on the lower right hand side of the Back Plane. These are used
for connecting the 24VDC power input supply.
There is an adjacent On/Off miniature toggle switch and re-settable thermal fuse.
The single 24DVC power supply is distributed to various output power channels. Each output power channel
has the appropriate DC-DC converter, regulator(s), filtering capacitors and status LEDs, etc.