Macurco TracXP TXP-C20, Инструкция по эксплуатации

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TXP-C20_Instruction_Manual_(Rev1.0)
REV – 1.0 [34-2900-0207-5 ] 26 | P a g e
Figure 4-5 – Optional Bridge Sensor Input Board
4.1.5 Optional Electrochemical Sensor Input Board
Important! Dual EC Sensor input PCB’s may only be installed into motherboard position P1.
The 10-bit dual Electrochemical Sensor Input option shown in Figure 4-6 allows these popular gas sensors to be
connected directly to the TXP-C20 without additional signal conditioning or transmitters. Each channel is equipped
with a preamplifier, bridge amplifier, sensor coefficient jumpers and a 2-position coarse gain jumper for setting the
gain of the bridge amplifier. Socketed resistors R4 and R16 control the gain of the preamplifier and are installed at
the factory (consult factory if sensor gas type is to be changed after shipment). Fault supervision circuitry forces the
TXP-C20 into a FAULT condition upon sensor failure or removal.
This option may also be configured to accept 4-20mA inputs for mixing an electrochemical sensor and a current loop
into the same board. Placing any channel’s 2 position TOXIC/4-20mA jumper into 4-20mA position and installing the
associated precision 100-ohm socketed resistor allows 4-20mA signals to be applied to its mA + / mA - terminals.
Bridge amplifiers are bypassed in this configuration.
4.1.6 Optional Discrete Relay PCB’s
Important! Discrete Relay Option PCB’s may only be installed into motherboard position P3.
The optional Discrete Relay PCB, shown in Figure 4-7, adds six 5-amp form C relays. Each relay is associated to one
of A1, A2 or A3 for channel 1 or 2. Many TXP-C20 applications utilize the standard equipped Relay 1 / Relay 2 (see
section 2.3.1) and do not require optional discrete relays for each of the 6 alarms events (2 A1’s, 2 A2’s & 2 A3’s).
All mechanical (dry contact) relays are rated at 5 Amp for 28 VDC and 250 ~VAC RESISTIVE loads.
IMPORTANT: Appropriate diode (DC loads) or MOV (AC loads) snubber devices must be installed with
inductive loads to prevent RFI noise spikes.