PEMTECH PT920-8FG User manual

MODEL PT920-8FG
8 CHANNEL
GAS MONITOR & CONTROLLER
Operator’s
Manual
Revision 2.0
March 2005
Pem-Tech, Inc.
Houston, Texas
U.S.A.

NOTICE
PEM-TECH INCORPORATED SHALL NOT BE LIABLE FOR
TECHNICAL OR EDITORIAL ERRORS OR OMISSIONS MADE
HEREIN, NOR FOR INCIDENTAL OR CONSEQUENTIAL
DAMAGES RESULTING FROM THE FURNISHING,
PERFORMANCE, OR USE OF THIS MATERIAL.
LIMITED WARRANTY
Pem-Tech, Incorporated warrants all the equipment to be free from defects in
workmanship and material. The products will operate in conformance with the
published specifications when subjected to intended and proper usage for the
period of one (1) year from the date of shipment.
The warranty provides only the benefits specified and does not cover defects
which result from acts beyond the control of PEM-TECH including, but not
limited to: damage by accident, negligence, tampering, or failure to operate in
accordance with the procedures outlined in the Operations Manual. PEM-
TECH’s liability under no circumstances will exceed replacement of the unit
claimed to be defective.
Tampering with the equipment and altering it for uses other than the intended
use or replacement of parts not supplied by the company, shall immediately
void and cancel all the warranties with respect to the affected products.
The warranties specified herein are in lieu of any and all other warranties,
express or implied. In no event, whether as a result of breach of warranty or
alleged negligence, shall PEM-TECH be liable for special or consequential
damages, including, but not limited to, loss of profits or revenue, loss of
equipment or down time costs.
2

SERVICE POLICY
Pem-Tech has service facility at the factory. For all the repairs contact at
our toll free number 1-800-379-3894 or visit our website www.pem-
tech.com
For all repairs call us for a Return Material Authorization number (RMA).
Inform us briefly the nature of the problem and obtain shipping address.
Properly pack the equipment before shipping. Also include your complete
shipping address and contact name and phone number.
For non-warranty repairs you must provide the limit to repair costs. State
if a quote for repair cost is required before you can authorize the repair
cost. For this an additional charge may be applicable.
NOTE:
1. For all the repairs under warranty, serial number must be legible on
the items being repaired.
2. Shipping point is FOB Houston.
3

TABLE OF CONTENTS
Specifications 5
Specifications for PT920-8FG Rack assembly 5
Specifications for Model PT920 Series Control monitor 6
Overview 7
Programmable Relays 7
Figure 1. PT920 Control module Front Panel diagram 8
Installation and Startup 9
Figure 2. PT920-8FG Enclosure dimension 9
Figure 3. System Overview drawing, 10
User termination, control modules in
Rack assembly
AC or DC power Input 11
Connecting sensors to monitor 11
Alarm wiring 11
Figure 4. Sensor and alarm wiring diagram 12
Startup 13
Apply Power 13
Normal Operation and alarms
Normal Operation 14
Alarms 14
Alarm Reset 14
Alarm Bypass 15
Programming Alarms 15
Programming Alarm Levels 16
Setting alarms as Latching or Non-Latching 17
Figure 5. PT920 Control Module diagram 18
Malfunction Condition 19
PartsList 20
4

SPECIFICATIONS
For PT920 Rack Assembly with Power Supply
MOUNTING: Wall or Panel Mount
ENCLOSURE: NEMA 4X Fiberglass Enclosure with clear
window
DIMENSIONS: 14”H x 12”W x 7”D
WEIGHT: 18 Lbs.
OPERATING -40 °F to +170 °F. (-20 °C to +70 °C.)
TEMPERATURE
POWER INPUT: 110-220 VAC or 24 VDC
HUMIDITY: 0 to 100% non condensing
ALARM RELAYS 3 alarm relays. Form “C” type rated 10 Amps
1 relay for Hi-Hi and 1 for Malfunction each
rated 5 Amps
TERMINATIONS Terminal blocks for sensor and alarm
connections for wire size 16-22 AWG
ALARM RESET Master alarm Reset switch to Reset Alarms
SWITCH on all control modules
5

SPECIFICATIONS
For PT920 Control Module
Display Range: 0 to 99 for Toxic and Combustibles
0 to 25.0 % for Oxygen deficiency ( 3 Digit
Display)
Input Signal: 4-20mA
Relay Ratings: 4 each Form C type relay contacts
Rated 5 Amps each
Low, High, High-High, and Malfunction
Field programmable alarm levels, Latching or
non-latching, Normally open or Normally
Closed contact
Visual Indicators: 4 Bright LEDs on the front panel to indicate
alarm status. Amber LED for Low Alarm
Red LEDs for High and High-High and
Malfunction Alarm
Power Input: 24 VDC power input. Power is supplied
to remote sensor & transmitter through a 2
Amp miniature fuse
Power Consumption: < 1 Watt normal operation for each control
module. Max of 2.4 watt with all relays active.
Alarm Reset Pushbutton switch on front panel to Reset
Alarms
Alarm Bypass Toggle Switch to Bypass / Inhibit Alarm relays
6

OVERVIEW
Pem-Tech model PT920 is a microprocessor based single channel monitor
that utilizes the latest digital design techniques in instrumentation. The
monitor uses an 8-bit high speed RISC processor with a highly accurate
analog to digital logic. The controller module receives the signal from
remote gas transmitters and displays the gas concentration. The 24VDC
power to the control module is supplied by the common bus on the back
plane (main connection board). The power to the remote sensor connected
to the module is routed through a miniature fuse on the module.
Standard features are:
•Displays current gas concentration on two (2) Digit Bright LED
display ( 3 digits display for Oxygen deficiency )
•Low, High, & High-High fully programmable alarm relay contacts.
•Alarms programmable via switches on the front panel
•Sensor Malfunction relay contact.
•Visual alarm indicators on the front panel.
•Alarm RESET and BYPASS switch.
•Optional RS485 Serial Communication for Remote data display
•Master Alarm Reset on the main rack assembly to Reset Alarms.
Programmable Relays
Each control module can be programmed for 3 distinct alarm levels. The
alarm levels can be easily programmed using Pushbutton switch provided
on the front panel of the control module. The alarm relays on the main
connection board are configured to have discrete Low level gas alarm for
Toxic (H2S) and combustibles (LEL) gases. Also present on the main
connection board are common High and Hi-Hi alarm relay contacts.
Below each control module there is a 2-pin jumper to select the module for
Toxic or Combustible type. Proper selection of this jumper will enable the
module to properly activate the low level alarm relay.
Also present is a common Sensor Malfunction alarm relay.
All relays are Form “C” type. Low and High alarm relays are rated
10Amps each while Hi-Hi and Malfunction are rated 5 Amps each.
7

Figure 1: PT920 Series Control Module
8
MODEL PT 920
BYPASS
ALARMS
NORMAL
HOUSTON, TX
MALF
RESET
HIGH
HI−HI
LOW
LEDs FOR VISUAL
ALARM INDICATION
DIGITAL DISPLAY
THUMB SCREW
PUSHBUTTON SWITCH
FOR ALARM RESET
TOGGLE SWITCH FOR
ALARM BYPASS
MODULE HANDLE

INSTALLATION AND START UP
PT920 Enclosure must be installed in a safe area. Figure 2 shows the
mounting holes for the fiberglass enclosure.
PT920-8FG rack assembly can house up to eight (8) PT920 series control
modules. On the front panel a captive screw is provided to secure the
control module to the rack. Do not use excessive force to tighten the
screw. Also a handle is provided to facilitate for insertion and removal of
the module from the rack assembly.
Figure 2. PT920 Enclosure. Dimensional drawing.
9

10
Figure 3. PT920-8FG Connection board with
8 PT920 Series control modules installed
LEL
H2S
++
AC IN
G
N
L
E
CH−1
−
E
+
CH−2
−
−
CH−5
E
E
+
−
CH−6
+
DC IN
−
PEM−TECH, INC.
HOUSTON, TX
PEM−TECH, INC.
HOUSTON, TX
CH−4
−
+
−
CH−3
E
E
+
C−
CH−8CH−7
−
+
E
E
NC
C
NO
NC
+NO
PEM−TECH, INC.
HOUSTON, TX
PEM−TECH, INC.
HOUSTON, TX
PEM−TECH, INC.
HOUSTON, TX
NO
NC
C
HIGH
C
LOW H2S
HI−HIFAIL
LOW LEL
NC
C
NO
NC
NO
PEM−TECH, INC.
HOUSTON, TX
PEM−TECH, INC.
HOUSTON, TX
PEM−TECH, INC.
HOUSTON, TX
CHANNEL 6
LEL MONITOR
MODEL PT 920
CHANNEL 3
H2S MONITOR
MODEL PT 920
ALARMS
NORMAL
BYPASS
RESET
MALF
HI−HI
HIGH
NORMAL
ALARMS
BYPASS
RESET
HI−HI
MALF
HIGH
CHANNEL 1
PPM H2S
LOW
H2S MONITOR
MODEL PT 920
PPM H2S
LOW
CHANNEL 2
H2S MONITOR
MODEL PT 920
NORMAL
ALARMS
BYPASS
NORMAL
ALARMS
BYPASS
RESET RESET
MALF
HI−HI
HIGH
MALF
HI−HI
HIGH
RESET
NORMAL
ALARMS
BYPASS
HI−HI
MALF
HIGH
CHANNEL 4
H2S MONITOR
MODEL PT 920
LOW
PPM H2S PPM H2S
LOW
% LEL
LOW
CHANNEL 5
LEL MONITOR
MODEL PT 920
POWER
O
1
GAS MONITOR
MODEL PT920−8FG
HOUSTON, TEXAS
NORMAL
ALARMS
BYPASS
RESET
NORMAL
ALARMS
BYPASS
RESET
MALF
HI−HI
HIGH
MALF
HI−HI
HIGH
NORMAL
ALARMS
BYPASS
RESET
MALF
HI−HI
HIGH
CHANNEL 7
LEL MONITOR
MODEL PT 920
LOW
% LEL % LEL
LOW
% LEL
LOW
CHANNEL 8
LEL MONITOR
MODEL PT 920
RESET
ALARM
MASTER ALARM
RESET SWITCH
AC POWER SWITCH
JUMPER SELECTION FOR
H2S / LEL CONTROL MODULE
24 VDC POWER IN
AC POWER IN
RELAY CONTACTS 10A EACH
LOW − H2S
LOW − LEL &
HIGH COMMON
SENSOR INPUTS
CH1 THRU CH8
HIGH−HIGH ALARM &
SENSOR FAIL
RELAY CONTACTS.
RELAY RATINGS 5 AMPS