Troubleshooting and Calibration of ABB Millmate Tension Gauge

2. Signal link interruption (no response from control panel)

Power supply inspection: First, measure whether the 24V DC power supply of the operation panel is normal. If using PxUB 201 insulated amplifier, it is necessary to check whether its power supply (+24V, 20-253V wide voltage) is normal and whether the output terminal is overloaded.

Network communication failure: If there is no communication between MC 400 and Millmate Operator Unit 400, check the TCP/IP settings of the local area network (LAN). Check if the network cable interface is loose and if the switch is in a crash state.

Relay board abnormality: If the system linkage or interlocking signal is lost, check the PFVK 128 relay board in the slot. This board is equipped with 4 conversion contact relays, with a power consumption of 20mA/relay. Check if the contact capacity (AC 250V/8A, DC 48V/1.2A) is stuck due to overload.

3. Control system configuration error

After replacing the new MC 400 controller or control panel, if the numerical display is chaotic, it is necessary to check the internal parameters. The MC 400 is equipped with rich built-in load cell tables, and engineers need to accurately select the model of the connected sensor (such as PFCL 201C or PFTL 201D) and the corresponding units (N, kN, MN, kp, t, lb, T) through the panel. If two or more rollers are used to measure the structure on site, it is necessary to ensure that the angle parameters (α, β) are inputted correctly, otherwise the system cannot pass the formula

FRot=T(sinα+sinβ)+Tare

F Rot=Calculate the actual tension of the strip steel using T (sin α+sin β)+Tare.

Standardized calibration and long-term maintenance recommendations

1. Zero calibration and tension calibration

When performing zero position calibration, it is necessary to ensure that there is no strip steel on the rolling mill and it is in a stationary state. The self diagnostic test system of MC 400 can assist in confirming the status of sensors. Tension calibration usually requires the use of standard weights or specialized calibration devices to verify the linearity deviation (≤± 0.5%) and repeatability error (≤± 0.05%) of the system by applying known forces.

In addition, the MC 400 provides adjustable filter times ranging from 5ms to 500ms. If the tension display of the rolling mill lags behind during acceleration and deceleration, the filtering time can be appropriately reduced; If the on-site mechanical vibration is extremely large, the filtering time can be increased to smooth the signal.

2. Protection and modular replacement in harsh environments

It is recommended to use fixed cable versions with protective hoses (such as PFCL 201CE or PFTL 101BE) on acid pickling or high-temperature annealing lines to prevent corrosive liquids from entering. For wall mounted installation, MC 400 can be placed in a dust-proof and splash proof cabinet (size 500 × 400 × 200mm) with a protection level of IP65.

When it is confirmed that the sensor is damaged and needs to be replaced, due to the fact that the sensor is made of a whole piece of stainless steel and has a large weight, lifting equipment needs to be used for assistance. Special attention should be paid to protecting the pins of the Cannon connector during disassembly and assembly, and it is strictly prohibited to plug or unplug with power on. After the replacement is completed, the load sensor model must be rechecked on the operation panel and a complete zero and range calibration must be performed before it can be put into production.