Robertshaw CR-103-A Series, Instruction Manual

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A. DESCRIPTION:
The Model CR-103 Averaging Relays are proportioning units
designed for use in industrial pneumatic control systems
where the application requires averaging 2, 3, 4, 5, 6 or 7
input pressure signals to obtain one output pressure signal.
For example: Where two or more transmitters (or controllers)
are measuring a common variable, the output pressures of the
transmitters (or controllers) can be averaged according to the
equation:
Output pressure
of Averaging Relay
Unused ports must be left open to atmospheric pressure.
B. DESIGN DATA:
INPUT PRESSURE RANGE:
0 to 20 psig (0 to 1.4 bar) nominal
50 psig (3.5 bar) maximum
OUTPUT PRESSURE RANGE:
0 to 20 psig (0 to 1.4 bar) nominal
50 psig (3.5 bar) maximum
SUPPLY PRESSURE: .................... 30 psig (2.1 bar) nominal
60 psig (4.2 bar) maximum
(Should always be at least
10 psig (0.7 bar) greater
than output pressure.)
BIAS ADJUSTMENT: ............
±
18 psig (1.2 bar) divided by
the number of input signals
OVERLOAD PROTECTION: .........100 psig (7 bar) will not
damage unit
AMBIENT TEMPERATURE LIMITS: ..... -40
°
F to 180
°
F
(-40
°
C to 82
°
C)
CONNECTIONS: ......................... 1/4" female NPT for input,
output and supply
WEIGHT:
2 input signals ..............................................2 lb. (0.91 kg)
7 input signals ...........................................3.5 lb. (1.59 kg)
C. PERFORMANCE DATA
ULTIMATE SENSITIVITY: ...................0.1% of full range
LINEARITY: ................................................1% of full range
HYSTERESIS: .............................Less than 1% of full range
REPEATABILITY: ..................................0.5% of full range
SUPPLY PRESSURE EFFECT:
Change in output pressure for 5 psig (0.35 bar)
supply pressure change, less than 1% of full range
AMBIENT TEMPERATURE EFFECT:
Change in output for a 75
°
F (24
°
C) ambient
temperature change, 0.5% of full range
AIR CONSUMPTION: .........................6.0 SCFH maximum
FOR MAXIMUM FLOW:
Supply Output Capacity ..................... 3.0 SCFM nominal
Exhaust Output Capacity ................... 3.0 SCFM nominal
D. MODEL NUMBER DESCRIPTION:
MODEL NUMBER INPUT
CR103-A2 2 Signals
CR103-A3 3 Signals
CR103-A4 4 Signals
CR103-A5 5 Signals
CR103-A6 6 Signals
CR103-A7 7 Signals
SECTION I - GENERAL INFORMATION
Sum of input pressure signals
±
spring bias
=
Number of input pressure signals