TRACO TIS600 power supply

Deployment and troubleshooting of TRACO TIS600 power supply in DC-UPS system

In process control, security, communication nodes, and industrial equipment that require power-off maintenance, ordinary switch mode power supplies can only solve the problem of "supplying power when there is mains power", but cannot solve the problem of "how long the system can last after the mains power disappears". TRACO POWER's TIS600-124UDS is a DC uninterruptible power supply system designed for this type of demand: it integrates a 600 W level 24 VDC switching power supply, external battery charging management, uninterrupted switching, and alarm relay into a DIN rail mounted metal housing. For on-site engineers, what really needs to be clarified is often not whether it is a 24 V power supply, but how to match the battery pack, how to set the charging current, what conditions trigger the power-off switch, how to connect the alarm contacts to the PLC, and where to start when "battery does not charge", "power-off does not switch", or "low battery false alarm" occurs.

Model positioning and electrical boundaries

TIS600-124UDS belongs to the DC-UPS version of the TIS series, with optional input of 115/230 VAC, nominal output of 24 VDC, maximum output power of 600 W, and maximum output current of 24 A. The difference between it and the ordinary TIS600-124 is the addition of a battery charger, battery switch logic, mains fault detection, and battery low voltage detection internally. The RED version is not the same type of product as the TIS xxx RED redundant version and TIS xxx SIG power fault signal version: the RED version is used for up to 5 parallel N+1 redundant systems, with decoupling diodes, current sharing lines, and unit fault alarms; SIG version provides AC Powerfall, DC OK, and Remote ON/OFF; The core of UDS version is battery management and uninterrupted backup. When selecting, the additional functions of UDS, RED, and SIG cannot be considered together, and the product documentation clearly states that redundant options cannot be combined with other options.

From the perspective of General Electric specifications, the TIS series has an input voltage range of 93-132 VAC and 187-264 VAC, with an input frequency of 47-63 Hz. The typical efficiency value of TIS600 is 88%, with a switching frequency of about 80 kHz, output ripple and noise less than 50 mV peak to peak, short-circuit protection of about 110% constant current limit and automatic restart, and overvoltage protection trigger point of about 140% of the nominal output. The working environment is between -25 ° C and 70 ° C, with a maximum relative humidity of 95% non condensing. If the temperature is above 50 ° C, the rating will be reduced by 2%/° C. That is to say, the TIS600-124UDS can be designed at 600 W at 50 ° C, but the available power will significantly decrease at 70 ° C. If the on-site cabinet has poor heat dissipation and battery charging and load coexist, it is easier to reach the power boundary. The shell is made of aluminum chassis with stainless steel cover, with a protection level of IP20, suitable for installation inside the control cabinet. It is clamped with a 35 mm DIN rail, and the TIS600 uses screw terminal blocks. When wiring, it should be constructed according to the terminal identification and torque requirements.

The working logic and battery management of DC-UPS

The normal working logic of TIS600-124UDS can be understood as "mains power priority, battery backup, automatic switching". When there is mains power, the power supply outputs 24 VDC to the load on one hand, and charges the external battery through an internal charger on the other hand; When the mains power disappears or falls below the detection threshold, the battery automatically connects to the DC output through internal switch logic, and the switching process does not interrupt the load power supply; After the mains power is restored, the battery is disconnected, the load is powered by the mains power again, and the charger resumes charging. The backup time is not limited by the power source itself, but depends on the battery capacity and load current. The battery pack provided in the product information is TIS 24-70 AP, 24 VDC/7.0 Ah, maximum allowable charging current of 2.4 A, charging voltage range of 27-27.6 VDC, temperature coefficient of about -36 mV/° C, charging working temperature of -15~50 ° C, load working temperature of -20~60 ° C, average standby life of about 4~5 years at 20 ° C, cable length of 1 m, wire diameter of 4.0 mm ², weight of about 5.9 kg. If TIS3000-124UDS is selected, it corresponds to a 3.2 Ah battery pack and a 1.2 A charging current.

The charging current of TIS600-124UDS is set at 2.4 A in the factory, with an adjustable range of 0.25-2.5 A. This parameter is crucial: the charging current is not necessarily the larger the better, it must be less than the maximum charging current allowed by the battery pack, taking into account battery temperature and service life. The data also shows that maintaining a charging current of less than 50 mA at 27.3 VDC indicates that the battery will enter a float charging state after being fully charged and will not continue to experience high current impact. When charging the battery, the output current will decrease by about 1.4 times the charging current. For example, when the charging current is set to 2.4 A, the available output current needs to be deducted by about 3.36 A. If the on-site load is close to 24 A and the battery is also in the charging stage, the total power and heat dissipation must be recalculated, otherwise there may be a drop in output voltage or intermittent overload.

The battery mode can be activated by connecting Pin 7 and Pin 8. During actual wiring, the function and polarity of these two pins should be confirmed according to the terminal diagram, and dry contacts or control signals that meet the requirements should be used to avoid mistakenly applying external voltage to the logic input. Even if the power supply itself has short-circuit protection for the battery circuit, it is recommended to install fast fuses according to the data requirements to reduce the risk of battery backflow and external short circuits. The battery pack is equipped with a resettable electronic fuse, which is fixed on the installation frame. When replacing it, a matching battery pack should be used. Do not mix and parallel batteries of different capacities, chemical systems, or aging degrees randomly.

Alarm relay, remote control and wiring

TIS600-124UDS provides two independent relay alarms: AC Powerfail and Battery Low. The detection condition for AC Powerfail is that the input voltage is below about 93 VAC (115 V range) or below about 187 VAC (230 V range), and relay A is activated. The closed contacts provided in the data are Pin 2 to Pin 3. The detection condition for Battery Low is that the battery voltage is below 22V, and the closed contact of relay B is Pin 5- Pin 6. The rated values of the two relay contacts are both 60 VDC/0.36 A maximum, and cannot directly drive high-power contactors or high-voltage circuits. They should be switched through intermediate relays or PLC digital inputs.

When wiring on site, it is recommended to connect the AC Powerfail to the PLC's "mains fault" diagnostic point and connect the Battery Low to the "battery will be depleted" warning point, rather than waiting until the low voltage shutdown to handle it. This can arrange a safe shutdown or switch to a backup power source before the battery is completely discharged. If the system needs to remotely disable battery mode, the control logic of Pin 7/8 should be confirmed: the data shows that battery mode can be activated by connecting Pin 7 and 8. Therefore, if these two pins are short circuited during maintenance, the system will enter battery mode after the mains power is lost; On the contrary, if it is necessary to prohibit battery input, it should be disconnected according to control requirements or controlled through relays. All alarm contacts and control lines should be routed separately from the power lines to avoid interference from noise sources such as frequency converters and contactors.

Installation, heat dissipation, and selection taboos

The TIS600-124UDS is installed on DIN rails, with a chassis size of approximately 243 mm wide, 177.2 mm high, and 82.6 mm deep. The weight is not directly given in the data, but the TIS600 of the same series belongs to the heavier 600 W power supply. When installing, ensure that the rail buckle is locked tightly and leave heat dissipation space above and below. It adopts natural cooling, and the temperature inside the cabinet must be controlled below 70 ° C. If it exceeds 50 ° C, the rating will be reduced by 2%/° C. If the battery pack and power supply are installed in the same cabinet, charging the battery will generate heat, and the battery life is sensitive to temperature. The standby life at 20 ° C is about 4-5 years, and the increase in temperature will significantly shorten the life. Therefore, the battery pack should be installed in a well ventilated and cooler location as much as possible, avoiding close contact with heating elements.

The most common mistake when selecting is to use the TIS600-124UDS as a regular 24V/600W power supply, ignoring the power consumption and output current deduction of battery charging; Or mistake the redundant function of TIS xxx RED for UDS also having it. The focus of UDS is battery backup, the focus of RED is multi power parallel redundancy, and the focus of SIG is signal contacts and remote switches, which cannot replace each other. If N+1 redundancy is required on site, the RED model should be selected; If only mains power failure and DC-OK signal are needed, SIG model can be selected; If you need to continue running after power failure, select UDS and match it with a battery pack. When replacing the old power supply, it is also necessary to check the battery voltage, capacity, charging current, alarm contacts, and Pin 7/8 control mode of the original system, rather than just looking at whether the output 24 VDC and power are similar.

On site debugging and common troubleshooting

Fault 1: The mains power is normal, but the battery is not charging or charging is slow. First, check if the charging current setting is set very low. The adjustable range of TIS600-124UDS is 0.25-2.5 A, and the factory setting is 2.4 A. Then confirm if the battery pack model is TIS 24-70 AP or a 24V lead-acid battery pack with matching parameters, and if the battery is equipped with a resettable electronic fuse and has been reset. Measure whether the charging voltage is within the range of 27-27.6 VDC and whether the battery temperature exceeds the charging range of -15 to 50 ° C. If the internal resistance of the battery increases due to aging, the charger may enter protection or the charging current may be limited. Battery testing or battery pack replacement should be performed. It is also necessary to confirm that Pin 7/8 has not been misconnected, causing the system to remain in battery mode for a long time, otherwise the charging logic will be abnormal when there is mains power.

Fault 2: Failure to switch or immediate shutdown after switching off the mains power. Firstly, confirm if the voltage of the battery pack is higher than 22V. If it is lower than this value, the Battery Low relay will activate, indicating that the battery may be nearing depletion. Check if the electronic fuse of the battery pack has tripped, if the battery cable is securely fastened, and if the wire diameter meets the requirement of 4.0 mm ². Confirm if the Pin 7/8 battery mode activation wiring is correct. If the contact is not closed, the battery mode may not be activated. If the load time is extremely short after switching, the load current and 7 Ah battery capacity should be calculated, and the battery should be checked for aging. When charging the battery, the output current will decrease by 1.4 times the charging current. If the load approaches full load, switching may trigger overload protection at the moment.

Fault 3: Battery Low alarm is frequent or false positive. Measure whether the battery voltage drops below 22V under load. If it is normal under no-load and shows a significant decrease under load, it is usually due to battery aging or insufficient capacity. Check if the charging has been insufficient for a long time. Setting the charging current too low, poor contact in the charging circuit, and high battery temperature can all cause undercharging. The battery testing function will periodically load the battery for a short period of time. If the internal resistance of the battery is high, it may trigger an alarm. At this point, do not simply short-circuit the alarm contacts, but replace the battery pack or adjust the charging parameters.

Fault 4: AC Powerfail alarm does not work or malfunctions. Confirm whether the input voltage is truly below the 93/187 VAC threshold, and measure whether the Pin 2-3 contacts of relay A are closed logically. If the contact is connected to the input module of the PLC, please note that the contact capacity is only 60 VDC/0.36 A and cannot be directly connected to high voltage or high current circuits. If frequent electromagnetic waves cause false alarms, the quality of the incoming voltage and whether the power input terminals are loose should be checked.

Fault 5: Insufficient output current or frequent overload protection. First, distinguish whether it is load overcurrent or charging occupancy. TIS600-124UDS has a maximum of 24 A, but 1.4 times the charging current will be deducted when charging the battery. If charged at 2.4 A, the available load current is about 20.6 A. Then check if the ambient temperature exceeds 50 ° C, and if it does, reduce the rating by 2%/° C. At 70 ° C, the available power significantly decreases. If the output is short circuited, the power supply enters a constant current limit of about 110% and automatically restarts; If there is a short circuit in battery mode, the system will shut down. It is necessary to eliminate the short circuit and check the battery quick fuse.

Fault 6: Short battery life or battery pack overheating. Check if the charging voltage is too high, if the charging current exceeds the maximum allowable value of the battery pack, and if the ambient temperature is too high. The battery pack should use matching charging voltage and temperature compensation, as long-term high-temperature float charging will accelerate water loss. It is recommended to conduct regular battery tests, record the backup time, and replace the entire set when the capacity significantly decreases. Do not mix old and new batteries.

Replacement and maintenance suggestions

When replacing TIS600-124UDS, the input voltage level, output load, battery pack model and capacity, charging current setting, Pin 7/8 wiring, AC Powerfail and Battery Low contact usage of the original system should be recorded first. Before installing the new power supply, confirm the DIN rail buckle and terminal torque. After wiring, do not connect the battery first. Measure the 24 VDC output and alarm contact status when powered on without load; Connect the battery pack again and measure the charging voltage and current; Perform a final power outage simulation to confirm that the switching time, load holding, and alarm actions meet the requirements. If the system has safety shutdown logic, power down testing should be conducted within the allowed maintenance window.

Daily maintenance should regularly check the cabinet temperature, battery appearance, terminal fastening, and battery backup time. The MTBF of TIS600-124UDS is about 300000 hours at 25 ° C, but the battery is a consumable and has a standby life of about 4-5 years at 20 ° C. The actual life is greatly affected by temperature and depth of charge and discharge. Only by designing the power supply, battery pack, charging parameters, alarm contacts, and load derating as a whole can TIS600-124UDS truly play an uninterrupted power supply role in the process control system, rather than becoming a new fault point when a fault occurs.