O S - 2 O p e r a t i o n P r o c e d u r e
OS-2 Wiring and Calibration Instructions
2.941
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2.185
55.50
5.118
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0
5.109
129.76
129.76
5.109
115
4.528
4.528
11
5
Installation
The OS-2 is suitable for indoor use only. Mount the unit as close to the source of potential refrigerant
leaks as possible. Some recommended considerations are as follows:
1. Mount the unit with the sensor pointing down.
2. Mount the unit in a location with low vibration. Strong vibration may cause a change in the condi-
tion of the internal membrane.
3. The sensor should be mounted 3’ to 5’ (0.9 to 1.5m) from the fl oor in equipment rooms or 1’ (0.3m)
above the fl oor in refrigeration pits.
4. The OS-2 should cover about 1000-1500 square feet with adequate air movement.
5. Mount at least 5’ (1.5m) from the exhaust fan.
6. Verify operation yearly.
Note: Make all connections in accordance with national and local codes. Not recommended for MRI
rooms.
1
6
3
.4
6
6
.4
3
6
150.76
5.936
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2.048
1
6
3
.4
6
6
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3
6
1
6
0
.0
2
6
.3
0
0
Green = normal levels
Red = alarm levels
STATUS:
SERVICE
NEEDED
OS-2S
Operation
The OS-2 has no power switch and is operational whenever it has suffi
cient operating power.
Operational status is indicated by a pair of LEDs on the front cover as shown in the table below:
AL
ARM
NC
I
C
OM
I
NO
OUT1-
OUT1+
P
WR-
P
WR+
Power Connection:
Use the Wiring Diagram (Figure 5) for reference with the following descriptions.
The OS-2 can be powered from 20 to 30 volts AC or DC. The operating power is connected to the four-position termi-
nal connector at the positions marked PWR+ and PWR- on the circuit board. The polarity of the power inputs are only
relevant when DC voltage is used to power the unit; if DC voltage is hook up in reverse polarity the unit will not power
up, but no damage to the controller will occur. Because the OS-2 uses a non-isolated power supply, a separate power
transformer for each unit is the safest confi guration when the analog outputs are used.
Analog Output Connection:
The OS-2 has an analog output option: the analog output is accessed at the 4-position terminal block.
Connect to positions labeled OUT 1+ and OUT 1-.
The analog output can be confi gured as voltage or current (refer to Table 3 in the Confi guring the Controller section for
more information). If the 4-20mA current output is selected, current will fl ow out of the terminal marked ‘+’ and return
through the terminal marked ‘-’.
This is not a loop powered device: do not attempt to power the OS-2 though the 4 – 20mA (analog output) connection as
this will void the warranty and likely damage the unit.
ALARM Relay Connections
The OS-2 has a SPDT, dry contact relay output
that is accessed at the three-position screw
terminal.
The top terminal is the relays NO contact,
•
The middle terminal is COM (common).
•
The bottom is the relays NC contact.
•
Potential Eff ects of Oxygen-Defi cient Atmospheres
O2 content
(%)
Eff ects and Symptoms (at atmospheric pressure)
20.9%
Normal air
19.50%
Minimum permissible oxygen level
15 – 19%
Decreased ability to work strenuously. May induce early symptoms in person
with coronary, pulmonary, or circulatory problems
12 – 14%
Respiration increase during exertion
10 – 12%
Poor judgemnt, lips turn blue
8 – 10%
Mental failure, fainting, unconsciousness
6 – 8%
4-5 minutes -recovery with treatment
6 minutes – 50% fatal
8 minutes – 100% fatal
4 – 6%
Coma onset in 40 seconds
source: excavationsafetynews.com
