Table of Contents
Advertisement
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
), carbon monoxide (CO), ethylene (C
2
primary indicators of incipient faults in oil-filled electrical equipment.
3.4.4 CPU Module
The CPU module (item 4 in Figure 3-2) 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 H201Ti's center
post and attaches to the I/O module (Section 3.4.6) using only two screws. Should the
need arise; the CPU module can be replaced very easily.
On the back side of the CPU module, an electrically isolated USB Type B connector
supports a 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 5, as from section 5.1.
3.4.5 USB Type B Connector for Communication
Located on the side of the CPU module (item 5 in Figure 3-2), the USB Type B female
connector allows local communications between the H201Ti and a host computer. This
connector is isolated from the main electronic circuitry. For wiring details, see Table D – 7
in Appendix D.
3.4.6 I/O Module
The Inputs/Outputs (I/O) module is built as an odd-shaped case that attaches to the
Hydran 201Ti'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.
• Alarm relays.
• Supervisory link manager.
Page 32
Hydran* 201i Instruction Manual
H
) and acetylene (C
2
4
H
) which are the
2
2
MA-033
Rev. 14.0, 12-Nov-18
Advertisement
Table of Contents
