CTI EM2 Series User manual
Installation and Operation Manual
EM2
ENTRANCE MONITOR
2EM2
Warning
Use this product only in the manner described in this manual.
If the equipment is used in a manner not specied by CTI,
the protection provided by the equipment may be impaired.
This equipment should be installed by qualied personnel.
EM2 3
Table of Contents
General description ........................................ 4
Installation ....................................................... 4
Locating the entrance monitor ................... 4
Installation guidelines ................................. 4
Wiring .......................................................... 5
Operation ....................................................... 10
Power-up.................................................... 10
Operator interface..................................... 10
Contrast ..................................................... 10
Home screen.............................................. 10
Alarm condition ......................................... 11
Status screens............................................ 11
Top Menu screen....................................... 12
Congurationmode .................................. 13
Test mode .................................................. 16
In/Out adjust.............................................. 17
Start-up ...................................................... 18
Maintenance................................................... 18
Specications ................................................. 20
Warranty......................................................... 21
For technical support, contact:
CTI
920 N Tradewinds Pkwy
Columbia, MO 65201
866-394-5861
www.ctiengineering.com
4EM2
General Description Installation
This manual covers the EM2-24 and EM2-120 entrance
monitors. The EM2-120 includes an installed AC-
DC power supply that allows for 120Vac input and
converts it to 24Vdc power for the EM2.
The EM2 terminates the gas sensor’s 4-20 mA signal,
and re-transmits the 4-20 mA signal to another analog
input device such as gas detection controller or plant
PLC. If no connection is made to the signal output
terminal, the unit will act as a stand-alone device.
Multiple entrance monitors can be installed in series,
providingexibleremoteviewingoptions.
The EM2 provides continuous real-time monitoring of
the sensor. Gas concentrations and alarm status are
indicated on the monochrome LCD display.
The EM2 is assembled into a wall mounted enclosure
designedfornon-classiedlocations.Thegassensor
(not included) is installed at the location where gas is
to be detected. The total distance between the sensor
and EM2, and the EM2 and the power supply should
notexceed1,000ft.
A calibration mode setting allows for sensor
maintenance and calibration without tripping the
relay and locks the analog output signal at 4 mA. The
onboardrelayhasadjustableon/otimedelaysto
prevent unnecessary cycling during a fault or alarm
condition.
Locating the Entrance Monitor
The EM2 can be installed indoors or outdoors and
should be installed for easy viewing and accessibility
by operating personnel.
Installation Guidelines:
• Mount on solid surface with minimal vibration.
• Mount readout in a general-purpose location only.
Do not install in a hazardous environment.
• Mount readout away from electromagnetic
interference.
• Protect readout from physical damage.
• If mounting on a wall with studs, the mounting
screws should be screwed into the studs.
Figure 1:
Dimensions
3.94"
6.0"
5.59"
6.1"
2.8" deep (EM2-24)
4.2" deep (EM2-120)
5
EM2
Opening the enclosure
The left and right hinges hold the top cover to the
base.
Insert a small (0.12" (3 mm) or smaller) slotted
screwdriver into the hinge key slot on the right hinge.
Inonequick,rmmotion,pryhingetotheright.This
should unclasp the hinge.
The left hinge is locked and typically shouldn't be
opened. If necessary, it can be unclasped by removing
the key lock.
Wiring
Electrical wiring must comply with all applicable codes.
Wiring Guidelines:
• Always use 3-conductor, insulated, stranded,
shielded copper cable for all sensor cables.
• Do not pull sensor wiring with AC power cables.
This can cause electrical interference.
• Be sure to land the shield conductors of the
sensor cables at the shield terminals of the sensor
connectors.
• Bonding between metallic conduit connections is
not automatic with the non-conductive enclosure.
Separate bonding must be provided.
• Use stranded, copper wire/cable with a minimum of
75°C rating (167°F).
• To maintain the IP rating of the enclosure, conduit
ttingsofthesameratingorbettermustbeused.
DC Power: (EM2-24)
Requires 24VDC, 350 mA (not including other
connected devices).
AC Power: (EM2-120)
100-240 VAC, 0.7A 50/60 Hz.
TheEM2-120isshippedwithyingleadsattachedto
the power supply terminals.
Hinge key slot
6EM2
Sensor Wiring:
• 4-20 mA, 261 Ohm input impedance.
• Refer to sensor manual for cable recommendations
(typically 18/3 shielded cable (General Cable
#C2535A or equivalent)).
• Cableshouldnotexceed1,000feettotallength
from the sensor to the power supply.
Relay Wiring:
• AC wiring must be run in separate conduit from the
sensor cables, if length of run is more than 10 ft.
• If a separate relay cable conduit hole is needed, do
not drill or punch hole on hinge sides of enclosure.
• The alarm relay has Form C dry contacts, and
is rated 8A @ 120-240 VAC or 5A @ 24 VDC (dry
contactsrequireexternalpowerconnection).The
relay is de-energized in the normal state (continuity
between C and NC), unless Failsafe is selected from
the menu. It will transition to the alarm state upon
sensor alarm. The alarm relay has a green status
LED to show the state of the relay. The green status
LED indicates when the relay is energized.
Stand-Alone and Feed-Through
Applications
The EM2 terminates the gas sensor’s 4-20 mA signal,
and re-transmits the 4-20 mA signal to another analog
input device such as gas detection controller or plant
PLC. If no connection is made to the signal output
terminal, the unit will act as a stand-alone device.
Stand-Alone wiring specications:
• Cable recommendations: 18/3 shielded cable
(General Cable #C2535A or equivalent).
• Cableshouldnotexceed1,000feettotallength
from the sensor to the power supply.
Feed-through wiring specications:
• Maximuminputimpedance:700Ohms.
• Cable recommendations: 18/3 shielded cable
(General Cable #C2535A or equivalent).
• Cableshouldnotexceed1,000feettotallength
from the sensor to the power supply.
7
EM2
Figure 2: Wiring Diagram (Stand-Alone application)
to +24V terminal of power supply (+V)
to Ground terminal of power supply (-V)
to Signal terminal of sensor
to +24V terminal of sensor
to Ground terminal of sensor
to Shield terminal of sensor
to horn/strobe
or other alarm
device
Failsafe O Failsafe On
to Ground terminal of power supply (-V)*
* Connect case ground and -V at power supply
8EM2
Figure 3: Wiring Diagram (Feed-Through application)
to Signal input of monitoring equipment
to +24V terminal of power supply (+V)
to Ground terminal of power supply (-V)
to case (earth) ground of monitoring equipment*
to Signal terminal of sensor
to +24V terminal of sensor
to Ground terminal of sensor
to Shield terminal of sensor
to horn/strobe
or other alarm
device
Failsafe O Failsafe On
* Connect case ground and -V at power supply
9
EM2
Example 1
Example 2
Next entrance
monitor or
sensor
Gas detection
controller, PLC or
power supply
Entrance monitor wiring example
1. Run cable from power source (PLC, controller or power supply) into “TO CONTROLLER” terminal.
2. Runcablefrom“TOSENSOR”terminaltothenextentrancemonitor.
3. Repeat step 2 until you have fed through every entrance monitor in sequence.
4. Onthelastentrancemonitor,nishbyrunningcabletothesensor.
5. If multiple EM2's are connected in series, additional power supplies and/or heavier gauge cable may be
required. Contact CTI for assistance.
10 EM2
Operation
Power-up
Beforeapplyingpower,makeanalcheckofallwiring
for continuity, shorts, grounds, etc. It is usually best to
disconnectexternalalarmsandotherequipmentfrom
the EM2 entrance monitor until the initial start-up
procedures are completed.
Operator Interface
All operator functions are performed from the
pushbuttons on the front of the panel. Below is a
list of the common key functions used for the LCD
operations:
Enter key is used to enter the Top menu, edit and save
congurationparametersandsavechangeswhile
exiting.
Escape key is used to go back to previous menu screen
orexitoutofaeldwithoutsavingchanges.
Up/Down/Left/Right keys are used to navigate the
menuandeldlists.
Insomeelds,thearrowkeyscanbeheldinto
dramatically increase the speed at which the number
increments/decrements.
Contrast
To adjust the contrast of the LCD, use the keys
from the Home screen or Status screen. The contrast
setting is shown on the Status screen.
Home screen
The Home screen of the LCD provides an at-a-
glance indication of the gas concentration, along
with gas type, unit of measurement, and alarm
status. The menu tables also allow for other units of
measurement, such as temperature, pressure, etc.
In cold temperatures, the LCD response time slows
down. The refresh rate will automatically slow down to
compensate for this to make it easier to read.
ENT
ESC
ALARM PPM
NH3
85300
This manual suits for next models
2
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