Weidmuller G128 User Manual

Weidmuller Ltd.
10 Spy Court
Markham, ON L3R 5H6
Tel: [phone]
Fax: [phone]

Weidmuller Inc.
821 Southlake Blvd.
Richmond, VA 23236 U.S.A.
Tel: [phone]
Fax: [phone]

ISO 9001 Registered

Electronic Interface Modules

G128 Ultra SlimPak®

Thermocouple Input, Field Configurable
Limit Alarm

• field configurable via DIP switches for different input­output combinations

• provides relay contact closure(s) at a preset
temperature input level

• field configurable input ranges for J, K, T, R, S, E and
B type thermocouples

• setpoints programmable HI or LO and failsafe or non­failsafe

• LED trip and input indicators

• 9 to 30Vdc powered

• CSA approved, UL recognized, CE marked

Description

Diagnostic LEDs

Output

Operation

Dynamic Deadband

The Ultra SlimPak G128 is a DIN rail mount, thermocouple input limit alarm with input terminal cold junction
compensation (cjc), dual setpoints and two contact closure outputs. The field configurable input and alarm
functions offer flexible setpoint capability. There are up to six temperature ranges available for each
thermocouple type to ensure accuracy and maximize setpoint resolution. A bipolar input switch is provided
for temperature ranges below 0°C.
The G128 is configurable as a single or dual setpoint alarm, with HI or LO trips, upscale or downscale
thermocouple burnout detection 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.

The G128 is equipped with three front panel LEDs. The first is a dual function LED labeled INPUT. This
green LED indicates DC power and input signal status. Active DC power is indicated by an illuminated LED.
If this LED is off, check line power and wiring connection. If the input signal is more than 110% of the full
scale range, the LED will flash at 8 Hz. Below 0%, the flash rate is 4 Hz.
Two red LED's indicate the relay state for each setpoint. An illuminated red LED indicates the tripped
condition.

The G128 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 set point and deadband.

The field configurable G128 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 low 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 non-failsafe). In the failsafe mode, a power failure results in an alarm state output.

LSI circuitry in the G128 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.

Table 1
G128 input range
selector - switch settings

Key: n ON

Figure 1

+

Load

Relay

Conta cts

Diode

(optio nal)

Figure 2: DC Inductive Loads

Relay

Conta cts

Figure 3: AC Inductive Loads

47 ohm

1/2W

47 ohm

1/2W

Load

MOV

0.1uF

0.1uF

Film

Film

Power

Power

-

Unless otherwise specified, the factory presets the Model G128 as follows:
Input: J Type Range: 0 to 350°C Output: Dual, SPDT
Trip: A: HI, B: LO Failsafe: No Deadband: A, B: 0.25%
The DC power input accepts any DC source between 9 and 30V, typically a 12V or 24Vdc source is used.
For other I/O ranges, refer to Table 1 and reconfigure switches SW1 and SW2 for the desired input type,
range and function.

Do not attempt to change any switch settings with power ap-plied. Severe damage will result!

1. With DC power off, position switch SW1-1, 2, 3 and SW2-1 through 6 for the desired input range (Table 1).

2. Set positions 4 and 5 of function switch "SW1" to ON for a HI trip setpoint or OFF for a LO trip setpoint
(Figure 4).

3. Set position 6 of function switch "SW1" to ON for non-failsafe operation or OFF for failsafe operation
(e.g. alarm trips upon power failure).

4. Set positions 7 and 8 of function switch "SW1" to upscale or down-scale burn-out.

1. After configuring the DIP switches, connect the input to a calibrated TC source and apply power. Refer to
the terminal wiring diagram.
NOTE: to maximize thermal stability, final calibration should be performed in the operation installation,
allowing approximately 1 to 2 hours for warm up and thermal equilibrium of the system.

2. Setpoint: set deadband at its minimum (20 turns counter clockwise) before adjusting the setpoint. With
the desired trip thermocouple millivolt input applied, adjust setpoint until the relay trips. For HI trip calibration,
start with the setpoint above the desired trip (20 turns clockwise). For LO trip calibration, start below the
desired trip (full counter clockwise).

3. Deadband: Set deadband to its minimum (20 turns counter clockwise). Set the setpoint to desired trip.
Adjust thermocouple millivolt input until relay trips. Readjust deadband to 5% (20 turns clockwise). Set
voltage/current input to desired deadband position. Slowly adjust deadband until relay untrips.

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 0.1HF pulse film capacitor (foil polypropylene recommended) of
sufficient voltage, and a 47M, 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).

Configuration

WARNING:

Calibration

Relay Protection and EMI
Suppression

Figure 4: G128 input range/function selection (SW1) Factory default settings

Rated data
Input

Range

Impedance

Maximum ratings / type of protection

Other input specification
Other input specification

Output

Range
Load
Zero / Span adjustment
Protection
Other output specification
Other output specification

Supply

Range
Consumption

General

Accuracy
Temperature coefficient (drift)
Transmission frequency
Response time. 90% span

Other general specification
Status LED
Isolation (# of ports)
Operating / Storage temperature
Housing (mounting)
Dimensions (L x W x H)
Wire range (conductor size)
Insulation stripping length
Tightening torque
Approvals

Ordering data

Ultra SlimPak
Heat sink (width)
Shunt resistor

Thermocouple temperature sensor
Thermocouple Type Temperature Range Thermocouple Type Temperature Range

B 0...1820ºC R 0...1760ºC
E -270...1000ºC S 0...1750ºC
J -210...760ºC T -270...390ºC

K -270...1372ºC DIP switch selectable
1 Meg M min.
±10Vdc
input bias current: <1.5HA

2 form C relays (2 SPDT), one set point per relay, gold flash / silver alloy contacts
2 set points independently adjustable over 100% of the selected input span, HI or LO, failsafe or non-failsafe
maximum 5A at 120Vac, 2A at 240Vac, 5A at 28Vdc (resistive load), minimum 10HA at 10mV
deadband adjustable from 0.25% to 5% of span
external relay contact protection required for inductive load switching
Electrical life: 105operations at rated load
Mechanical life: 107operations no load
DC voltage
9 to 30Vdc, inverter isolated

1.5W typ., 2.5W max. (300mA inrush at 9Vdc)

0.2% for temp. >0°C, 0.3% for temp. <0°C
±0.05% of full scale/°C, max.

<250mS in normal mode, dynamic deadband: relay status will change when proper setpoint/process
condition exists for 100mS

input green (>110% of input: 8Hz, <-10% of input: 4Hz), 2 setpoint red (ON: tripped, OFF: safe)
1800V (3 port) between contacts, input and power
0°C to 55°C / -15°C to 70°C
EG12 (TS32 and TS35)
90mm x 17.7mm x 112.7mm max.
22-12AWG (0.5-4.0mm2)
7mm

0.4-0.8Nm
CSA (file LR-42272), UL (file E99775), CE marked (EMC dir. 89/336/EEC, LV dir. 73/23/EEC)

Cat. No.
G128 (factory calibration: 0 to 350ºC (J-type,), A-HI/B-LO, non-failsafe)
HS01-A (1.6mm) (conditionally required depending on installation, see heat sink data)

Note: G128-000X where X is the revision level

Specifications subject to change without notice. 99990009 - 8/98 Printed in Canada

TS32 RAIL

TS35 RAIL