Note
Neither Emerson, Emerson Process Management, nor any of their affiliated entities assumes responsibility for the selection, use, and maintenance of any product. Responsibility for the selection, use, and maintenance of any product remains with the purchaser and end-user.

Available Configurations

See table 1

Process(1) Sensor Range (Input Signal(1))

Type: Temperature between -73 and 371°C (-100 and 700°F). See table 2 for available ranges
Minimum Span(1): 60°C or 100°F
Maximum Span(1): 300°C or 600°F

Output Signal(1)

Proportional or Proportional-Plus-Reset Range: ■ 0.2 to 1.0 bar (3 to 15 psig) or ■ 0.4 to 2.0 bar (6 to 30 psig)
Differential Gap Output: ■ 0 and 1.4 bar (0 and 20 psig) or ■ 0 and 2.4 bar (0 and 35 psig)
Action: Field-reversible between ■ direct (increasing sensed temperature increases output pressure) or ■ reverse (increasing sensed temperature decreases output pressure)

Process Scale

Matched to the range of the sensing element as standard. Optional(2) scales available.

Supply and Output Connections

1/4 NPT internal

Supply Pressure Requirements(3)

See table 3

Supply Pressure Medium

Air or natural gas(4)

Remote Set Point Pressures

■ 0.2 to 1.0 bar (3 to 15 psig) or ■ 0.4 to 2.0 bar (6 to 30 psig)

Maximum Allowable Pressure in Closed Vessel (For Temperature Element Assembly)(5)

9.5 mm (3/8-Inch) Diameter Temperature Bulb: 69 bar (1000 psig)
14.3 mm (9/16-Inch) Diameter Temperature Bulb: 34.5 bar (500 psig)

Construction Materials

See table 4

Controller Adjustments

Proportional Band(1): 5 to 500% of process scale range
Reset(1) : Adjustable from 0.01 to more than 74 min per repeat (from 100 to less than 0.0135 repeats per min)
Differential Gap(1) Controllers: Adjustable from 1 to 100% of process scale range
Set Point: Continuously adjustable from 0 to 100% of the scale range.

Controller Performance

Repeatability(1): 0.4% of output span
Dead Band(1): Less than 0.4% of process scale range
Time Constant of Temperature Bulb: For a 96 93°C (200°F) span, 6 to 12 seconds (bare bulb in agitated liquid)

Steady-State Air Consumption(1,6,7)

0.2 to 1.0 Bar (3 to 15 psig) Output: 0.10 normal m3/hr (3.5 scfh)
0.4 to 2.0 Bar (6 to 30 psig) Output: 0.14 normal m3/hr (5.0 scfh)

Delivery Capacity(5)

0.2 to 1.0 Bar (3 to 15 Psig) Output: 5.6 normal m3/hr (240 scfh)
0.4 to 2.0 Bar (6 to 30 Psig ) Output: 9.9 normal m3/hr (350 scfh)

Exhaust Capacity(5)

0.2 to 1.0 Bar (3 to 15 Psig) Output: 4.6 normal m3/hr (186 scfh)
0.4 to 2.0 Bar (6 to 30 Psig ) Output: 7.0 normal m3/hr (295 scfh)

Operative Ambient Temperature Limits(3,8)

-40 to 70°C (-40 to 160°F)

Hazardous Area Classification

Complies with the requirements of ATEX Group II Category 2 Gas and Dust

Housing

Designed to NEMA 3 (Weatherproof) and IEC 529 IP54 specifications

Mounting

Controller can be mounted on ■ actuator, ■ panel, ■ wall, or ■ pipestand

Approximate Weight

4.5 kg (10 lb)

• Easy Maintenance—Simple design allows fast, easy maintenance and minimal spare parts inventory.
• Easy Adjustment—Adjusting the set point, adjusting the zero and span of the process pointer, and switching between direct and reverse action are accomplished quickly and without special tools. Also, no interaction occurs when the set point and proportional band are adjusted.
• Vibration Resistance—The simple design and low mass of internal parts allow the controller to withstand the vibrations found in most plant environments.
• Highly Visible Display—Two red pointers on a 114 mm (4-1/2 inch), white-on-black scale show process temperature and deviation from set point at a glance. Two other gauges monitor supply and output pressures.
• Low Air Consumption—The relay and nozzle design reduces steady-state air consumption to as low as 0.10 normal m3/h (3.5 scfh).
• Corrosion Resistance—Tough plastic housing resists corrosive environments. Internal constructions are available to resist corrosive supply pressure media such as sour gas.

Simplified Relay Maintenance

A clean-out wire provides a fast, easy means of cleaning the relay primary orifice during service.

Pressure Protection for the Case

A rubber plug in the plastic case pops out to vent excessive pressure buildup inside the case before structural damage can occur.

Easy Direct/Reverse Switching

Controller action can be switched from direct to reverse or vice versa by simply loosening the screws on the proportional band cover and moving the cover out to rotate the proportional band knob to the desired action (see figure 2).

Easy Mode Conversion

Conversion from proportional to proportional-plus- reset control requires the addition of a reset valve and two pieces of tubing. Conversion from proportional to proportional-plus-reset-plus-rate control requires the addition of a reset/rate valve and three pieces of tubing. Conversion from proportional to differential gap control requires the addition of one piece of tubing. These conversions require removing the controller from the case.

Anti-Reset Windup

Anti-reset windup is available with proportional-plus- reset and proportional-plus-reset-plus-rate controllers. A relief valve can be adjusted to limit reset windup on either increasing or decreasing output.

Remote Set Point

The capability of adjusting the set point from a remote location is available as an option with all 4196 Series controllers.

Auto/Manual Capability

An optional internal auto/manual station permits smooth, bumpless transfer between automatic control and manual operation without disturbing the controller output. A positive-acting, two-position switch, showing either automatic or manual control mode, is clearly visible with the controller cover closed.

External Feedback

In controller override applications, this option minimizes reset windup in the secondary controller. This option is available only with the two-mode (4196B Series) controllers.

Proportional-Only Controllers (4196A Series)

The input element is connected to the process pointer and to the flapper by connecting links. As the process temperature increases (in a direct-acting controller), the flapper moves toward the nozzle, restricting flow through the nozzle and increasing nozzle pressure. When this occurs, relay action increases the output pressure (delivery) of the controller. Output pressure is fed back to the proportional bellows. The action of the proportional bellows counters the flapper movement that resulted from the process temperature change and backs the flapper away from the nozzle until the controller reaches a point of equilibrium.
The set point adjustment changes the proximity of the nozzle and flapper as does a change in process temperature except that, when the set point is changed, the nozzle moves with respect to the flapper.
The proportional band adjustment knob positions the nozzle on the flapper. Increasing (widening) the proportional band moves the nozzle to a position on the flapper where less flapper motion occurs, decreasing the gain of the controller. Decreasing (narrowing) the proportional band moves the nozzle toward a position where more flapper motion occurs, increasing the gain. Controller action is changed from direct to reverse by turning the proportional band adjustment knob to position the nozzle to a point on the flapper where the direction of the flapper motion versus input motion is reversed (see flapper detail in figure 3). With the controller in the reverse-acting mode, an increase in process temperature causes a decrease in output pressure.

Proportional-Plus-Reset Controllers (4196B Series)

This controller operation is similar to that of proportional-only controllers except that output pressure is fed back to the reset bellows as well as to the proportional bellows. In operation, proportional-plus-reset controllers minimize the offset between the process temperature and set point.

Proportional-Plus-Reset-Plus-Rate Controllers (4196C Series)

Figure 4 shows details of the reset/rate option. Controllers with this option have a rate valve, an adjustable restriction that momentarily maintains the controller gain to accelerate the corrective action for slow temperature systems. A proportional-plus- reset-plus-rate controller responds to a change in process temperature as follows:
First, the rate action delays the gain reduction just long enough to allow the system to respond to the change, but not long enough for the system to become unstable. Then, the low gain provided by the proportional action keeps the system stable. Finally, reset action slowly increases the gain and returns the process temperature toward set point.

Differential Gap Controllers (4196S Series)

In this version, feedback pressure does not counteract the change in flapper position. Instead, the change is reinforced because feedback pressure is piped directly to the reset bellows only. This construction causes the controller output to switch from full supply pressure to zero pressure or vice versa.

Anti-Reset Windup Option

Anti-reset windup is available on all 4196B and 4196C Series controllers and is designated by the suffix letter F in the type number. The differential relief valve operates when the difference between proportional bellows pressure and reset bellows pressure reaches a predetermined value. Anti-reset windup reduces overshoot of the process temperature that can result from large or prolonged deviation from set point. This option can be adjusted to operate on either increasing or decreasing output pressure.

Remote Set Point Option

The optional capability to change the controller set point from a remote location is available with all 4196 Series controllers. This option is designated by the suffix letter M in the type number.

Auto/Manual Option

Controllers with the auto/manual option (designated by the suffix letter E in the type number) have piping on the output side of the relay as shown in figure 6. Supply pressure to the relay is also applied to the manual loader. The manual loader, functioning as a
regulator, applies pressure to one side of the plastic tube and to the auto/manual switch. Output pressure from the relay registers on the other side of the plastic tube as well as in the auto/manual switch.
When the auto/manual switch is in the MANUAL position, the output of the manual loader becomes the output of the controller. The output of the manual loader is adjustable using the manual loader knob.
When the auto/manual switch is in the AUTO position, the output of the relay is channeled through the switch to become the output of the controller.
Before the auto/manual switch is operated, the output of the relay must equal the output of the manual loader to avoid bumping the process. Adjusting the set point varies the pressure on the left-hand side of the plastic tube. Adjusting the manual loader knob varies the pressure on the right-hand side. When the pressures are equal, the metal ball is centered in the tube. Pressure imbalance will force the ball to one end of the tube where it forms a seal, blocking air flow through the tube.

External Feedback Option

External feedback is available with all 4196B Series controllers. Controllers with this option have an external process connection on the bottom of the controller case (see figure 9). This connection breaks the positive feedback (reset) loop inside the controller and brings it outside (see figure 5). The connection allows the positive feedback loops of two controllers (primary and secondary) to be tied together when the controllers are used in an override application. Thus connected, the feedback loop of the secondary controller tracks the primary controller, minimizing reset windup.

Applications

When ordering, specify:
1. Description of the service
2. Temperature range of the process
3. Ambient temperature
4. Velocity of the process fluid (if measuring the temperature of a process fluid flowing through a pipe)
5. Pressure in the process vessel (if closed)
6. Bushing or thermowell. Specify either busing or thermowell (If required) when the temperature bulb is used in a closed vessel. Refer to figure 8 for available sizes. Specify straight-shank or tapered-shank thermowell. Tapered-shank thermowells, with their high strength-to-weight ratio, permit operation in higher process fluid velocities than do straight-shank thermowells.

Construction

Refer to the Specifications section and the Construction Features section. Carefully review each specification and feature, specifying your choice whenever a selection is offered. Pipestand mounting hardware will be supplied unless some other mounting method is specified.
Refer to table 1 for type numbers (add R to any type number if reverse action is desired).

Note
Neither Emerson, Emerson Process Management, nor any of their affiliated entities assumes responsibility for the selection, use, and maintenance of any product. Responsibility for the selection, use, and maintenance of any product remains with the purchaser and end-user.