Commissioning; Commissioning The Drive; Operation And Maintenence; Testing - Danfoss VLT PTC Thermistor Card MCB 112 Operating Manual

VLT® PTC Thermistor Card MCB 112
Operating Guide

4 Commissioning

4.1 Commissioning the Drive

Procedure
1.
For commissioning the STO, follow the instructions in the section Commissioning of the VLT
Torque Off Operating Guide.
- a. Read and understand the safety instructions.
b.
- Activate the STO.
- c. Set the parameters (automatic or manual restart).
d.
- Perform STO commissioning test.
- e. Ensure system configuration security.
2.
Test the correct function of the MCB 112 by simulation of the sensor resistance at terminals T1 and T2. This test must also
be done at maintenance services.
- a. Perform a short-circuit test: Resistance 20 Ω in parallel to sensor terminals T1 and T2.
- b. Perform a line interruption test: Disconnect sensor line at terminal T1 or T2.
- c. Perform a temperature test: Increase resistance 50–1500 Ω to 4000 Ω. The tripping function is stated in the LCP and
can be reset manually when the failure is removed. The output states of X44/12 and X44/10 shall be as shown in
the illustration in
cations.

4.2 Operation and Maintenence

4.2.1 Testing

The safety function must be tested with regular intervals.
Test once per year, or within the maintenance cycle of the plant.
For recurring examinations of electrical systems in hazardous areas, the inspection period must be kept within 3 years. The safety
test recognizes 1 fault (1oo1 - 1 out of 1). One fault between safety tests can cause loss of protection.

4.2.2 Monitoring Sensor Resistance

+24 V
0 V
3650 Ω
1500 Ω
T1/T2
High=1
X44/12
Low=0
High=1
X44/10
Low=0
Illustration 6: Monitoring of Sensor Resistance
1 Short circuit
2 Tripping is not saved and is not protected against 0 voltage
A current continuously monitors the resistance of the sensors. In cold state, the resistance is <250 Ω per sensor (sensor circuit
<1.5 kΩ). The output to terminal X44/12 is high=1. The resistance of the sensor rises rapidly at nominal response temperature TNF.
At a resistance of 3–4 kΩ, output to terminal X44/12 changes to low=0. The devices also switch off if the sensor wire short-circuits
(<20 Ω, or if the sensor or wire is interrupted. It switches back on automatically when the temperature has decreased by approxi-
mately 5 °C (41 °F).
Depending on the number of sensors, the following tripping and release temperatures are achieved with respect to TNF (nominal
response temperature of the sensors).
18 | Danfoss A/S © 2022.08
4.2.2 Monitoring Sensor Resistance. Pay attention to the ambient conditions, see chapter Specifi-
Commissioning
®
Frequency Converters Safe
1)
2)
!
AQ267038105120en-000101 / 130R0104