Product Description
G118 Alarm
G118 Alarm
The Ultra SlimPak G118 is a DIN rail mount, RTD input limit alarm with dual setpoints and two contact closure outputs. The field configurable input and alarm functions offer flexible setpoint capability. There are up to eight temperature ranges available for each RTD type to ensure accuracy and maximize setpoint resolution.
The G118 is configurable as a single or dual setpoint alarm, with HI or LO trips and failsafe or non-failsafe operation. Also included are adjustable deadbands (0.25 to 5% of full scale input) for each setpoint and a flexible DC power supply which accepts any voltage between 9 and 30VDC.
Diagnostic LEDs
The G118 is equipped with three front panel LEDs. The first is a dual function LED labeled IN (input). This green LED indicates line power and input signal status. Active DC power is indicated by an illuminated LED. If this LED is off, check DC power and wiring connection. If the input signal is more than 110% of full scale, the LED will flash at 8 Hz. Below -10%, the flash rate is 4 Hz.
Two red LEDs indicate the relay state for each setpoint. An illuminated red LED indicates the tripped condition.
Output
The G118 is equipped with two SPDT (form C) relays, rated at 120VAC or 28VDC at 5 amperes. Each of these relays is independently controlled by the field configurable setpoint and deadband.
Operation
The field configurable G118 limit alarm setpoints can be configured for HI or LO, failsafe or non-failsafe operation. Each of the setpoints has a respective HI or LO deadband. In a tripped condition, the setpoint is exceeded and the appropriate red LED will illuminate. The trip will reset only when the process falls below the HI deadband or rises above the LO deadband (see Figure 1). For proper deadband operation the HI setpoint must always be set above the LO setpoint.
In failsafe operation, the relay is energized when the process is below the HI setpoint or above the LO setpoint (opposite for nonfailsafe). In the failsafe mode, a power failure results in an alarm state output.
Dynamic Deadband
LSI circuitry in the G118 prevents false trips by repeatedly sampling the input. The input must remain beyond the setpoint for 100 milliseconds, uninterrupted, to qualify as a valid trip condition. Likewise, the input must fall outside the deadband and remain there for 100 milliseconds to return the alarm to an untripped condition. This effectively results in a “dynamic deadband” —based on time— in addition to the normal deadband.
Configuration
Unless otherwise specified, the factory presets the Model G118 as follows:
| Input: | Platinum (100Ω) |
| Range: | 0 to 250°C |
| Output: | Dual, SPDT |
| Trip: | A:HI, B:LO |
| Failsafe: | No |
| Deadband: | A, B: 1.0% |
The DC power input accepts any DC source between 9 and 30V; typically a 12V or 24VDC source is used (see Accessories).
For other I/O ranges, refer to Tables 1 through 3 and reconfigure switches SW1 and SW2 for the desired input type, range and function.
- With DC power off, position input switches 1 through 6 on “SW2” for RTD type (see Table 1).
- Set position 1 through position 4 of input range switch “SW1” for the desired RTD type and input temperature range (Table 3).
- Set position 5 and 6 of input range switch “SW1” to ON for a HI trip setpoint or OFF for a LO trip setpoint (Figure 4).
- Set position 7 of input range switch “SW1” to ON for non-failsafe operation or OFF for failsafe operation (e.g. alarm trips upon power failure).
Calibration
- After configuring the DIP switches, connect the input to a calibrated RTD source or a resistance decade box and apply power. (Figure 6).
- Setpoint Calibration: Before adjusting the setpoint, adjust deadband pot to its minimum (20 turns counter clockwise). With the desired trip RTD resistance input applied, adjust setpoint pot until the relay trips. For HI trip calibration, start with the setpoint pot above the desired trip (20 turns clockwise). For LO trip calibration, start with the setpoint pot below the desired trip (20 turns counter clockwise).
- Deadband Calibration: Set deadband pot to its minimum (20 turns counter clockwise). Adjust the setpoint pot to desired trip. Adjust RTD resistance input until relay trips. Readjust deadband pots to 5% (20 turns clockwise). Set RTD resistance input to desired deadband position. Slowly adjust deadband (counter clockwise) until relay untrips.
Relay Protection and EMI Suppression
When switching inductive loads, maximum relay life and transient EMI suppression is achieved using external protection (see Figures 2 and 3). Place all protection devices directly across the load and minimize all lead lengths. For AC inductive loads, place a properly-rated MOV across the load in parallel with a series RC snubber. Use a 0.01 to 0.1mF pulse film capacitor (foil polypropylene recommended) of sufficient voltage, and a 47W, 1/2W carbon resistor. For DC inductive loads, place a diode across the load (PRV > DC supply, 1N4006 recommended) with (+) to cathode and (-) to anode (the RC snubber is an optional enhancement).
TECHNICAL SPECIFICATION (G118)
Inputs
- Sensor Types:Pt100, Pt500, Pt1000 (0.00385W/W/°C); Cu10, Cu100; Ni120, NiFe604
- Sensor Connection: 3-wire.
Excitation Current (Max)
<2mA for Pt100, Pt500, Pt1000, Ni120, Cu100 or NiFe604 <10mA for Cu10
Leadwire Resistance
40% of base sensor resistance or 100Ω (whichever is less), maximum per lead.
Leadwire Effect
Less than 1% of selected span over entire leadwire resistance range.
Input Protection Normal Mode:
Withstands ±5VDC.
Common Mode (Input to Ground):
1800VDC, max.
LED Indicators Input Range (Green):
- >110% input: 8Hz flash
- >-10% input: 4Hz flash
Setpoint (Red):
- Tripped: Solid red
- Safe: Off
Limit Differentials (Deadbands)
.25% to 5% of span
Response Time
- Dynamic Deadband: Relay status will change when proper setpoint/process condition exists for 100msec.
- Normal Mode (analog filtering): <250mSec, (10-90%)
- Setpoints Effectivity: Setpoints are adjustable over 100% of the selected input span
- Repeatability (constant temp.): ±0.2% of full scale
Stability
- Line Voltage: ±0.01%/%, max.
- Temperature: ±0.05% of full scale/°C, max.
Common Mode Rejection
DC to 60Hz: 120dB / >60Hz: 100dB
Isolation
1800VDC between contacts, input and power
EMC Compliance (CE Mark)
- Emissions: EN50081-1
- Immunity: EN50082-2
- Safety: EN50178
Humidity (Non-Condensing)
- Operating: 15 to 95% (@45°C)
- Soak: 90% for 24 hours (@65°C)
Temperature Range
- Operating: -15 to 55°C (5 to 131°F)
- Storage: -25 to 75°C (-13 to 158°F)
Power Consumption:
1.5W typical, 2.5W max.
Supply Range:
9 to 30VDC, inverter isolated
Relay Contacts
2 SPDT (2 form C) Relays, 1 Relay per setpoint
Current Rating (resistive)
- 120VAC: 5A
- 240VAC: 2A
- 28VDC: 5A
- Material: Gold flash over silver alloy
- Electrical Life: 10^5 operations at rated load
- Mechanical Life: 10^7 operations
Weight
0.56lbs.
Agency Approvals
- CSA certified per standard C22.2, No. 0-M91 and 142- M1987 (File No. LR42272)
- UL recognized per standard UL508 (File No.E99775)
- CE Compliance per EMC directive 89/336/EEC
