Fairchild T7800 Instrucciones Para La Instalación Operación Y Mantenimiento página 7

MAINTENANCE
To clean the Orifice, use the following procedure:
1. Shut off the valve that supplies air to transducer. It
is not necessary to remove the Transducer from
the air line.
2. Remove the Orifice Assembly (6) from the unit. For
more information, see Figure 11.
3. Clean with alcohol and dry with compressed air.
Parts must be completely dry before
NOTES: 1.
reassembling.
If the standard maintenance procedure
2.
does not correct the problem, install the
appropriate service kit.
HAZARDOUS AREA CLASSIFICATION
FM (Factory Mutual) Approvals:
Intrinsically Safe:
Catalog Versions: TAFI7800, TDFI7800
Class I,II,III Div 1 Groups CDEFG T4
ED-18970; Entity
I/O AEx ia IIB T4
-40°C to +80°C
Non-Incendive:
Class I,II,III Div 2 Groups ABCDEFG T6
ED-18970; NIFW
-40°C to +80°C
Enclosure Type 4X
Intrinsically Safe:
Catalog Versions: TTFI7800, TRFI7800
Class I,II,III Div 1 Groups CD T4
ED-18970; Entity
I/O AEx ia IIB T4
-40°C to +80°C
Non-Incendive:
Class I,II,III Div 2 Groups ABCD T6
ED-18970; NIFW
-40°C to +80°C
Entity Parameters
1
Vmax = 28VDC
2
Imax = 100mA
3
Pmax = 0.7W
1
Vmax = Maximum Voltage
2
Imax = Maximum Current
3
Pmax = Maximum Power
Nonincendive Field Wire Parameters (NIFW)
1
Vmax = 30VDC
2
Imax = 120mA
1
Vmax = Maximum Voltage
2
Imax = Maximum Current
4
Ci = 12nF
5
Li = 0mH
4
Ci = Capacitance
5
Li = Inductance
3
Ci = 0uF
4
Li = 0mH
3
Ci = Capacitance
4
Li = Inductance
TROUBLESHOOTING
Table 6. Troubleshooting
Problem
No output
Leakage
Low or improper
Span adjust
Erratic operation
WARNING: Transducer failure could result in output
pressure increasing to supply pressure
and possibly causing personal injury or
damage to equipment.
CSA (Canadian Standards Association) Approvals:
Intrinsically Safe: (4-20 mA only)
(TDCI7800, TACI7800)
Class I, Division 1, Groups C and D;
Class II, Division 1, Groups E, F, and G;
Type 4 Enclosure;
Rated 4-20 mA, 30 VDC Maximum;
Temperature Code T6.
(TTCI7800, TRCI7800)
Class I, Division 1, Groups C and D;
Temperature Code T6.
Approvals are valid when connected through a Shunt
Zener Diode Safety Barrier meeting the following
parametric requirements:
System Single Channel Polarized Rated: 28.5V
Type 1:
Max. 300 Ohm Min.
System Dual Channel Polarized Rated: 28.5V Max.
300 Ohm Min. and 10V Max. 50 Ohm Min.
Type 2:
System
Dual Channel Polarized Rated: 28.5V Max. 300
Type 3:
Ohm Min. and 28V Diode return per channel.
Division 2 Approvals: (4-20 mA only)
(TDCI7800, TTCI7800, TRCI7800)
Class I, Division 2, Groups A, B, C and D;
Rated 4-20 mA, 30 VDC Maximum;
Temperature Code T6.
(TACI7800)
Class I, Division2, Groups A, B, C and D;
Class II, Division 2, Groups E, F, and G;
Type 4 Enclosure;
Rated 4-20 mA, 30 VDC Maximum;
Temperature Code T6.
HAZARDOUS AREA CLASSIFICATION
CONTINUED ON THE NEXT PAGE
7
Solution (check)
• Supply pressure
• Clogged orifice
• Connections
• Zero and Span adjust
• Low supply pressure
• Output leakage
• DC signal
• Loose wires or connections
• Liquid in air supply