The loss model of the power panelboard is based on the sum of partial power losses from circuit breakers, fusible switches, motor starters, and bus bars with enclosures.
Electrical Equipment Used in Power Panelboard Molded Case Circuit Breakers (MCCBs) Switches Voltage rating: 600 VAC Voltage ratings: 600 or 690 vac Ampere rating: 15 to 1200 amps Ampere rating: 16 to 630 amps Thermal magnetic trip Three poles Three poles J Class-Fuse RK1 Class-Fuse Voltage rating: 600 VAC Voltage ratings: 250 or 600 VAC Ampere ratings:15 to 600 amps Ampere ratings: 70 to 600 amps Single pole Single pole Motor Starters Voltage ratings (Max.
By substituting for the partial power loss models of electrical equipment in power panelboard previously described
The power panelboard loss model is valid under the conditions that are shown in Table 7.
Conditions of Power Panelboard Loss Models Location Indoor Maximum operating voltage 600 VAC Frequency 60 Hz Loads Three phase balanced currents Copper bus bar conductivity 98.9% IACS Enclosure Galvanized steel sheet Room temperature 25 [degrees] C (77 [degrees] F) Bus bar temperature rise 65 [degrees] C (149 [degrees] F) To estimate the heat gain from power panelboards, the loss models of the panelboard with main breaker and given by Equation 17 and the panelboard with main fusible switch given by Equation 18 were used in a Visual Basic program that was linked to a spreadsheet.
A power panelboard with a circuit breaker as the main disconnecting device will be installed in a room and its dissipated power loss has to be estimated to size the HVAC equipment.
Electrical Equipment of Power Panelboard in the Example Main Branch Main breaker: Main bus bar: Rating = 1000 amps Rating = 1200 amps Load = ?, lf= ?
Power Losses in the Example Main Branch Main breaker: Main bus bar: 107.4 W 58.94 W Secondary Branches Breaker 1: Breaker 2: 18.19 W 7.87 W Breaker 3: Breaker 4: 8.34 W 8.34 W Breaker 5: J Fuse/switch 1: 8.34 W 12.61 W J Fuse/ switch 2: J Fuse/ switch 3: 25.90 W 22.42 W NEMA 1 FVNR motor starter: NEMA 3 FVNR motor starter: 14.57 W 26.68 W NEMA 2 FVNR motor starter: 30.51 W Total Power Loss: 350 W The estimated heat gain rate from the power panelboard is 350 watts.
The power panelboard loss model at part-load presented in this paper was based on the sum of partial power losses of each panelboard component.
The main goal of this paper is to create a model to predict heat gain from power panelboards for three phase balanced loads and 60 Hz so that HVAC equipment in industrial plants and buildings can be sized accordingly.
The power panelboard is classified by its current rating which is either 250, 400, 600, 800, or 1200 amps and by its dimensions which consist of height, bus bar length, width, and depth.
Circuit breakers used in power panelboards, motor control centers and switchboards are molded case circuit breakers rated at 600 VAC and between 15 and 2500 amps.