Danfoss VLT FC 102 Programming Manual

Also see for VLT HVAC Drive FC 102: Operating instructions Service guide Programming guide Installation guide Installation guide

Contents

2-11 Brake Resistor (ohm)Range: Function:Sizerelated*[ 5.00 -65535.00Ohm]Set the brake resistor value in Ω.This value is used for monitoringthe power to the brake resistor inparameter 2-13 Brake PowerMonitoring. This parameter is onlyactive in frequency converters withan integral dynamic brake.Use this parameter for valueswithout decimals. For a selectionwith 2 decimals, useparameter 30-81 Brake Resistor(ohm).2-12 Brake Power Limit (kW)Range: Function:Sizerelated*[ 0.001 -2000.000 kW]Parameter 2-12 Brake Power Limit(kW) is the expected average powerdissipated in the brake resistor overa period of 120 s. It is used as themonitoring limit forparameter 16-33 Brake EnergyAverage and thereby specifies whena warning/alarm is to be given.To calculate parameter 2-12 BrakePower Limit (kW), the followingformula can be used.Pbr, avg W = Ubr2 V × tbr sRbr Ω × Tbr sPbr,avg is the average powerdissipated in the brake resistor, Rbris the resistance of the brakeresistor. tbr is the active breakingtime within the 120 s period, Tbr.Ubr is the DC voltage where thebrake resistor is active. Thisdepends on the unit as follows:T2 units: 390 VT4 units: 810 VT5 units: 810 VT6 units: 943 V/1099 V for D – FframesT7 units: 1099 VNOTICEIf Rbr is not known, or if Tbr isdifferent from 120 s, thepractical approach is to runthe brake application, readparameter 16-33 Brake EnergyAverage and then enter this+ 20% in parameter 2-12 BrakePower Limit (kW).2-13 Brake Power MonitoringOption: Function:NOTICEThis parameter is only activein frequency converters withan integral dynamic brake.This parameter enables monitoringof the power to the brake resistor.The power is calculated based onthe resistance (parameter 2-11 BrakeResistor (ohm)), the DC-link voltage,and the resistor duty time.[0] * Off No brake power monitoring isrequired.If power monitoring is set to [0] Offor [1] Warning, the brake functionremains active even if themonitoring limit is exceeded. Thismay lead to thermal overload ofthe resistor. It is also possible togenerate a warning via a relay/digital output. The measuringaccuracy of the power monitoringdepends on the accuracy of theresistance of the resistor (betterthan ±20%).[1] Warning 120s Activates a warning when thepower transmitted over 120 sexceeds 100% of the monitoringlimit (parameter 2-12 Brake PowerLimit (kW)).The warning disappears when thetransmitted power drops below80% of the monitoring limit.[2] Trip 120s Trips the frequency converter andshows an alarm when thecalculated power exceeds 100% ofthe monitoring limit.[3] Warning & trip120sActivates both of the above,including warning, trip, and alarm.[4] Warning 30s[5] Trip 30s[6] Warning & trip30s[7] Warning 60s[8] Trip 60s[9] Warning & trip60s[10] Warning 300s[11] Trip 300s[12] Warning & trip300s[13] Warning 600sParameter Descriptions VLT® HVAC Drive FC 10272 Danfoss A/S © 10/2019 All rights reserved. M001000133