GE Hydran 201i, Инструкция по эксплуатации

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Internal Components
Part 17997 Rev. 6, March 2011 2-7
Combustible gases dissolved in the oil pass through a selectively-permeable membrane into
an electrochemical gas detector (located inside the H201 sensor). Within the detector, the
gases combine with oxygen to produce an electrical signal that is then measured by an
electronic circuit and converted to ppm. The H201 sensor is sensitive to hydrogen (H
2
),
carbon monoxide (CO), ethylene (C
2
H
4
) and acetylene (C
2
H
2
) which are the primary
indicators of incipient faults in oil-filled electrical equipment.
2.4.4 CPU Module
The CPU module (item 4 in Figure 2-2 on page 2-5) contains a microprocessor which is the
brain of the Hydran 201T
i . It is built as a circular, flat case. It fits snugly over the H201T i ’s
center post and attaches to the I/O module (Section 2.4.6 on page 2-7) using only two
screws. Should the need arise, the CPU module can be replaced very easily.
On the back side of the CPU module, a surge-protected DB-9 male connector supports an
RS-232 communication port, and a 36-pin connector mates with the I/O module.
A six-key membrane keypad and a liquid crystal display (LCD), consisting of two lines of
16 characters, are located on the front of the CPU module. Their operation and the menu
system are explained in Chapter 4.
2.4.5 DB-9 Male Connector for the RS-232 Link
Located on the back of the CPU module (item 4 in Figure 2-2 on page 2-5), the DB-9 male
connector (item 5 in Figure 2-2 on page 2-5) allows local RS-232 communications between
the H201T
i and a host computer. This connector is protected against surges. For wiring
details, see Table D-7 on page D-4.
2.4.6 I/O Module
The Inputs/Outputs (I/O) module is built as an odd-shaped case that attaches to the
Hydran 201T
i ’s heating plate by means of three screws accessed from the outside. It can
thus be replaced rapidly, should it be required.
The I/O module consists of the following components:
• Regulated power supply
• All I/O circuits
• Hydran 201 sensor’s analog circuit