Installation Data Dynamic Braking What These Instructions Contain These instructions contain the necessary information to select, configure and install dynamic braking. By completing How to Select a Brake first you will be able to determine whether or not dynamic braking is required for your application. How Dynamic Braking Works When a motor turns faster than the synchronous speed set by drive output frequency, the motor can generate power which is returned to the drive. Without dynamic braking, power returned to the drive bus can cause bus voltage to rise above the rated limit of the drive. This condition can occur if power returned to the drive exceeds 20% of drive rating. 1305 drives have an overvoltage trip feature to detect this condition and shut down the drive if necessary. When dynamic braking is added to 1305 drives, excessive power is dissipated in the brake resistors. Increased braking (over 20%) can now take place and an overvoltage trip condition will not occur within the increased limits of the brake. The 1305 drive monitors the DC bus. When the drive senses a rise in bus voltage and braking action is required, the brake will be activated. Activating the brake adds resistors across the DC bus, providing a load to dissipate motor power generated during braking. When the DC bus voltage is lowered to within acceptable limits and braking is no longer required, the dynamic brake will be deactivated and the brake resistors will be disconnected from the DC bus. The dynamic brake is designed to be activated only when required to dissipate excessive energy returned to the DC bus. Typically the brake should be activated (on) only during drive deceleration and ramp-to-stop. How to Select a Brake To begin selection the following application information must be obtained. The nameplate horsepower of the motor HP. The nameplate base speed of the motor N in RPM. The speed profile of the motor. N2 RPM N1 RPM t1 t2 AB0650A where: N1 = The motor’s minimum speed in RPM. N2 = The motor’s maximum speed in RPM. t1 = The motor’s cycle time in seconds. t2 = The motor’s decel time in seconds. 2 Installation Data Dynamic Braking The motor inertia, the nameplate gear reduction ratio, and the load inertia. Motor Inertia wk2M Gear Ratio GR Input RPM Output RPM Load Inertia wk2L AB0649A Step 1 Determine the Rated Motor Torque TQM = 5250 x HP N HP = The nameplate horsepower of the motor N = The nameplate base speed of the motor TQM = 5250 x TQM = LBFT Step 2 Determine the Total Inertia wk2t = wk2M + [wk2L x (GR)2] wk2t = +[ )2] x( wk2M = The motor inertia wk2L = The load inertia GR = The total reduction ratio Output RPM Input RPM wk2t = LBFT2 Step 3 Determine the Required Braking Torque TQB = wk2t x [N2 - N1] 308 x t2 TQB = [ ]x[ 308 x [ - ] ] wk2t N2 N1 t2 = The total inertia = The motor's maximum speed = The motor's minimum speed = The motor's decel time TQB = LBFT Step 4 Determine the Required Percent of Braking Torque TQ% = TQB x 100 TQM TQ% = [ [ ] x 100 ] TQB = The required braking torque TQM = The rated motor torque TQ% = % If TQ% is less than 20%, dynamic braking is not required. The inherent braking of the drive should be sufficient to handle the application requirements. If TQ% is 20% or more, a dynamic brake is required. Continue to Step 5. 3 Installation Data Dynamic Braking Step 5 Determine the Maximum Generated Braking Torque Three factors limit the application of dynamic braking. The first is the brake assembly rating PT — The peak power the brake assembly can absorb at any instant regardless of the time limit. The second is the average power that the brake assembly can absorb during one braking duty cycle — PA. The third is the duty cycle or the number of times the brake assembly can be operated over a given period of time — DC. TQB = The required braking torque N2 = The motor's maximum speed PM = TQB x N2 7,000 PM = [ ]x[ 7,000 PM = ] kW PM must be less than or equal to the Brake Assembly Rating listed in Table 1. If PM exceeds the PT value shown, the corresponding drive/brake configuration will not be able to produce the braking torque required for your application, and the drive will trip on an overvoltage fault. Increasing the decel time t2, reducing the load inertia wk2L, or doing both will lower TQB and PM. Table 1 Drive Output Ratings HP kW Dynamic Brake Kits PT kW 230V AC 2 1.5 1305KAA12 3 2.2 1305KAA12 17 1.7 460V AC 1/2 0.37 1305KBA03 3/4 0.55 1305KBA03 1 0.75 1305KBA03 2 1.5 1305KBA06 3 2.2 1305KBA06 5 4 1305KBA09 Step 6 Determine the Average Power Generated in One Cycle TQB = The required braking torque N1 = The motor's minimum speed N2 = The motor's maximum speed PA = TQB x [N1 + N2] 14,000 PA = [ 4 ]x[ 14,000 + ] PA = kW 0.85 17 1.7 3.4 Installation Data Dynamic Braking Step 7 Determine the Ratio of the Average Power to the Brake Assembly Rating PA = The average power generated in one cycle PT = The brake assembly rating from Table 1 P% = PA PT P% = [ [ ] ] P% = % Find the intersection of P% and the motor’s decel time t2 in the chart below. If the point of intersection is below the curve, the average power of one cycle is within the brake’s limits. If the point is above the curve, the average power is beyond the brake’s limits but may be reduced by increasing the motor’s decel time t2, reducing the load inertia wk2L, or doing both. P% 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 10 20 30 40 50 60 Decel Time t2 in Seconds 70 80 90 100 AB0647A 5 Installation Data Dynamic Braking Determine if the Duty Cycle is within the Brake's Capability DC = t2 x 100 t1 T1 = The motor's cycle time T2 = The motor's decel time DC = [ [ DC = ] x 100 ] % Find the intersection of P% and the motor’s decel time DC in the chart below. If the point of intersection is below the curve, the duty cycle is within the brake’s limits. If the point is above the curve, the duty cycle is beyond the brake’s limits but may be modified by increasing the motor’s cycle time t1. P% 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0 5 10 15 20 25 30 Duty Cycle DC in % 6 35 40 45 50 AB0648A Installation Data Dynamic Braking KAA12, KBA03, KBA06 Dimensions, Weights, and Conduit Entry Locations IMPORTANT: These dynamic braking models can be used with any 1305 drive. D C H Conduit Entry (Outer Dimension) 28.5mm (1.12 in.) Dia. E B Conduit Entry (Inner Dimension) 22.2mm (0.87 in.) Dia. F XXXXXXX XXXXXXXXXX XXXXXX XXXXXXXXXX XXXXXXXXX XXX XXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXX XXXXXXXX XXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXX XXXXXXXXXXXX XXXXX A (Front) Brake Model (Side) Approx. Ship Wt. kg (lbs.) HP Voltage Catalog Number 2&3 230V 1305KAA12 3.4 (7.5) 1/2, 3/4, 1 460V 1305KBA03 3.4 (7.5) 2&3 460V 1305KBA06 3.7 (8.1) (Bottom) AB0570D A Width mm (in.) B Height mm (in.) C Depth mm (in.) D mm (in.) E mm (in.) F mm (in.) G mm (in.) H mm (in.) 101.6 (4.00) ( ) 327.7 (12.90) ( ) 153.9 (6.06) ( ) 50.8 (2.00) ( ) 315.0 (12.40) ( ) 114.6 ((4.51)) N/A (N/A) ( ) 12.7 (0.50) ( ) 7 Installation Data Dynamic Braking KBA09 Dimensions, Weights, and Conduit Entry Locations ATTENTION: Use Dynamic Braking Model KBA09 with Series B or later 1305 drives only. Component damage or drive failure will occur if Model KBA09 is used with Series A 1305 drives. Braking Module KBA06 may be used on a 5 HP, Series A, 1305 drive (3 HP braking torque maximum). 1.85 Conduit Entry (Outer Dimension) 28.5mm (1.12 in.) Dia. E Conduit Entry (Inner Dimension) 22.2mm (0.87 in.) Dia. B G XXXXXXX XXXXXXXXXX XXXXXX XXXXXXXXXX XXXXXXXXX XXX XXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXX XXXXXXXX XXXXXXXXXXXXXXXXXXXXXXX XXXXXXXXXXXX H XXXXXXXXXXXX XXXXX C D A (Front) Brake Model 8 HP Voltage Catalog Number 5 460V 1305KBA09 F (Side) (Bottom) AB0571D Approx. Ship Wt. kg (lbs.) A Width mm (in.) B Height mm (in.) C Depth mm (in.) D mm (in.) E mm (in.) F mm (in.) G mm (in.) H mm (in.) 5.9 (13) 184.2 (7.25) 327.7 (12.90) 153.9 (6.06) 50.8 (5.00) 315.0 (12.40) 114.6 (4.51) 127.0 (1.63) 12.7 (0.50) Installation Data Dynamic Braking Specifications Braking Torque 100% torque for 20 seconds (typical). Duty Cycle 20% (maximum), every 100 seconds. Temperature 0°C to 50°C (32°F to 122°F). Humidity 0% to 95% noncondensing. Atmosphere NEMA Type 1 Cannot be used in atmospheres having corrosive or hazardous dust, vapor, or gas. Altitude Derating 0 to 1,000 meters without derating. Enclosure Type IP20, modified NEMA Type 1. Codes and Standards UL, cUL. ATTENTION: Electric Shock can cause injury or death. Remove all power before working on this product. For all dynamic brake ratings, DC brake power is supplied from the drive DC Bus. Hazards of electrical shock exist if accidental contact is made with parts carrying bus voltage. A bus charged indicator on the drive provides visual indication that bus voltage is present. Before proceeding with any installation or troubleshooting activity, allow at least 60 seconds after input power has been removed for the bus circuit to discharge. Mounting Requirements Dynamic brake enclosures must only be installed in the vertical position. Select a location using the following guidelines. S Each dynamic brake enclosure must be mounted outside of any other enclosure or cabinet and exposed to unrestricted circulating air for proper heat dissipation. Allow a minimum of 304.8 mm (12 in.) between brake enclosures and all other enclosures or cabinets including the drive. S The brake enclosure must be mounted within 30 m (100 ft.) of the drive. Top Air Flow AB0572B 9 Installation Data Dynamic Braking Recommended Brake Mounting Configuration Unobstructed Drive 304.8 mm (12 in.) Minimum 30 m (100 ft.) Maximum Brake 304.8 mm (12 in.) Minimum Unobstructed Brake Fuse AB0545C All dynamic brakes are internally fused to protect brake components. When replacing the brake fuse, use only the type and size specified below. Replace the brake if the fuse blows repeatedly. IMPORTANT: Brakes are not repairable. Dynamic Brake Fuse Type Rating KAA12 F1 Gould Shawmut A60Q152 15A, 230V KBA03 F1 Gould Shawmut A60Q102 10A, 460V KBA06 F1 Gould Shawmut A60Q102 10A, 460V KBA09 F1 Gould Shawmut A60Q102 10A, 460V Wiring Scheme Bul. 1305 DB Enable Parameter #11 GRD GRD L1 R L2 S L3 T +DC BRK T1 (-DC) U 1305 Brake T2 V T3 W F1 BRK GRD +DC AB0546B 10 Installation Data Dynamic Braking Terminal Block Wiring Capacity Required minimum DC Power Wiring Sizes in mm2 and (AWG). Table 2.A Screw Size, Wire Size, and Torque Specifications Terminal TB1 Screw Size M4 Max./Min. Wire Size mm2 (AWG ) 4/0.75 (10/18) Maximum Torque Nm ( lbins. ) 1.81 (16) Setup ATTENTION: The dynamic brake unit contains a thermostat to guard against overheating and component damage. If the duty cycle, torque setting and/or ambient temperature exceeds the specifications listed in this publication, the thermostat is designed to trip, blow an internal fuse, and disable the brake. If reduced braking torque represents a potential hazard to personnel, auxiliary stopping methods must be considered in the machine and/or control circuit design. 1305 Parameter Settings Parameter 11 DB Enable must be set to “Enable” when dynamic braking is installed. Refer to your 1305 Programming Manual for programming procedures and record the changes for future reference. 11