Fisher 546 Instruction Manual page 3

Available Configurations
Type 546: Electro-pneumatic signal transducer with
explosion-proof case and cover
Type 546S: Similar to Type 546 except designed
for intrinsically safe, non-incendive, or dust-ignition
applications
Type 546NS: Similar to Type 546 except provided
with EPDM elastomers for use in elevated tempera-
ture and radiation environments
All transducer types can be ordered with or without
a 67 Series filter regulator. A 2 inch (51 mm) circu-
lar supply pressure gauge may be mounted on the
regulator
(1)
Input Signals
Type 546 and 546NS: 1 to 5 mAdc, 4 to 20 mAdc,
10 to 50 mAdc, 1 to 9 Vdc, or two-way split range
using any half of one of the standard input signal
spans
Type 546S: 4 to 20 mAdc, or
Mutual only, a two-way split range using either half
of the 16 mAdc span. Signal must not exceed 30
Vdc, 20 mAdc
Internal Resistance of Torque Motor
1 to 5 mAdc Input Signal: 2500 120 ohms (stan-
dard) or 12,000 50 ohms (temperature-compen-
sated circuit)
4 to 20 mAdc Input Signal: 176 10 ohms
10 to 50 mAdc Input Signal: 90 10 ohms
1 to 9 Vdc Input Signal: 1300 50 ohms (tempera-
ture-compensated circuit)
(1)
Output Signals
(1)
Ranges:
For 546 and 546NS: 3 to 15 psig (0.2 to 1.0 bar), 6
to 30 psig (0.4 to 2.0 bar), 3 to 27 psig (0.2 to 1.9
bar), 0 to 18 psig (0 to 1.2 bar), or 0 to 33 psig (0 to
2.3 bar)
For 546S: 3 to 15 psig (0.2 to 1.0 bar), 6 to 30 psig
(0.4 to 2.0 bar), 3 to 27 psig (0.2 to 1.9 bar), or 0 to
33 psig (0 to 2.3 bar)
Action: Type 546 and 546NS are field-reversible
between direct and reverse action. The Type 546S
is available with either direct or reverse action but
cannot be reversed in the field.
(1)
Supply Pressure
Recommended: 5 psig (0.3 bar) higher than upper
range limit of output signal
Maximum: 50 psig (3.5 bar)
1. These terms are defined in ISA Standard S51.1-1979.
2. Scfm—Standard cubic feet per minute (60 F and 14.7 psia). Normal m
3. Performance values are obtained using a Type 546 or Type 546S transducer with a 4 to 20 mAdc input signal and a 3 to 15 psig (0.2 to 1 bar) or a 6 to 30 psig (0.4 to 2 bar) output signal.
Ambient temperature is 73 F (24 C). A transducer with other input or output signals might exceed these values. Reference accuracies of 3.5% can be expected with output ranges starting
near zero psig.
Type 546, 546S, and 546NS
Table 1. Specifications
Maximum Steady-State Air Consumption
At 20 psig (1.4 bar) Supply Pressure: 0.35 scfm
(0.6 normal m
At 35 psig (2.4 bar) Supply Pressure: 0.50 scfm
(0.8 normal m
Maximum Output Air Capacity
At 20 psig (1.4 bar) Supply Pressure: 8.0 scfm
(13.4 normal m
At 35 psig (2.4 bar) Supply Pressure: 11.5 scfm
(19.3 normal m
Performance
Actuator Loading Time: See figure 7
Reference Accuracy: 0.75% of output signal
span
Independent Linearity:
span
Open Loop Gain:
For Factory
Frequency Response:
at 20 Hz with transducer output signal piped to a
typical instrument bellows with 12 inches (305 mm)
of 1/4 inch tubing
Operative Ambient Temperature Limits
–40 to +150 F (–40 to 66 C)
Electrical and Enclosure Classification
Refer to the Hazardous Area Classification bulletins
and the transducer nameplate (see figure 2)
Housing: NEMA 3R and CSA ENC 3 rating (NEMA
3R mounting orientation requires vent location to be
below horizontal. Vent is shown in figure 10, key 69)
Adjustments
Zero and Span Adjustments: Screwdriver adjust-
ments located inside case (see figure 5)
Connections
Supply Pressure: 1/4-inch NPT female located on
side of case, (or located on the Type 67 AFR filter-
regulator if mounted)
Output Pressure: 1/4-inch NPT female located on
side of case
Vent: 1/4-inch NPT female with screen located on
relay
Electrical: 1/2-inch NPT female located on bottom
of case
Approximate Weight (Transducer Only)
9 pounds (4.1 kg)
3
/hr—Normal cubic meters per hour (0 C and 1.01325 bar absolute).
3
/hr)
3
/hr)
(2)
3
/hr)
3
/hr)
(3)
(1)
0.50% of output signal
(1)
26
(1)
Gain is attenuated 3 dB
(1,2)
(1)
3