Quick Reference Guide
®
Vaisala CARBOCAP
Dioxide Module GMM112 and
Transmitter GMW115
– GMM112 compact diffusion
aspirated CO
module for OEM
2
applications
– GMW115 CO
transmitter for wall
2
mounting
– Measurement range 0 ... 2000 ppm or
0 ... 5000 ppm CO
2
– Ideal for HVAC applications
ELECTRICAL CONNECTIONS
mA
V
0
B
Carbon
A
0
24V
See Figure 3 for wire terminals.
Powering
The products require a nominal 24 VDC/VAC power supply
maintaining a voltage of 18 ... 30 VDC or 20 ... 26 VAC for all
load conditions and all mains voltages. Although the power input
includes a half-wave rectifier, it is recommended to use a DC
supply to avoid current peaks.
Connections to 24 VAC Power Supply
Connecting more than one transmitter to a single 24VAC
transformer forms a common loop and increases the risk of a
short-circuit. Therefore, a separate floating supply for each
transmitter is recommended (see Figure 1).
If several transmitters share a common transformer, the phase (~)
must always be connected to the 24 V connector in each
transmitter (see Figure 2).
Figure 1 Connection of Separate AC Supplies (Recommended)
Figure 2 Connection of Single AC supply to Several Transmitters
Signal 4 ... 20 mA
Signal (+) 0 ... 10 V
Signal (-)
RS-485 Signal B
RS-485 Signal A
Power supply (-)
Power supply (+) 24 VDC/VAC
0601-001
0601-002
MOUNTING AND DIMENSIONS
Dimensions
mA
mA
V
V
0
0
B
B
A
A
0
0
24V
24V
Ø3.2
30
60
0601-004
Figure 3 GMM112 Module Connections and Dimensions
66.3
60
84
Figure 4 GMW115 Transmitter Dimensions
0601-005