Baldor ID15J1F50-ER, Installation And Operating Manual

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A-2 Dynamic Brake Hardware MN715J
Dynamic Braking (DB) Hardware Continued
General Machinery Load Calculations:
1. Calculate braking duty cycle:
Duty Cycle +
Braking Time
Total Cycle Time
2. Calculate deceleration torque:
T
Decel
+
RPM change Wk
2
308 time
* Friction
(Lb * Ft)
where: T
Decel
= Deceleration torque in lb-ft
Wk 2 = Inertia in lb-ft 2
time = In seconds
3. Calculate watts to be dissipated in dynamic braking resistor:
Watts
+
T
Decel
ǒ
S
max
*
S
min
Ǔ
Duty Cycle
(0.0712)
where: S
max
= Speed to start braking
S
min
= Speed after braking
4. Multiply watts calculated in step 3 by 1.25 to allow for unanticipated
loads (safety factor).
15J Catalog Numbers with an “ER” Suffix
These controls include a factory-installed dynamic braking transistor. If
dynamic braking is required, use an optional external RGA brake resistor.
See RGA assemblies.
RGA Assemblies include braking resistors completely assembled and mounted
in a NEMA 1 enclosure. A listing of available RGA assemblies is provided in Table
A-2. The minimum resistance “Minimum Ohms” shown in the table is the
minimum resistor value that can be connected to the control without causing
damage to the internal dynamic brake transistor for ER controls.
115VAC controls must use 56 ohms or greater.
230VAC controls must use 56 ohms or greater.
460VAC controls must use 120 ohms or greater.
Table A-2 Dynamic Braking Resistor Assemblies (RGA)
Continuous
Rated Watts
Minimum Ohms
Rated Watts
30 60 120 150
100 RGJ160 RGJ1120 RGJ1150
200 RGJ260 RGJ2120 RGJ2150
300 RGJ360 RGJ3120 RGJ3150
600 RGA630 RGA660 RGA6120
1200 RGA1230 RGA1260 RGA12120
2400 RGA2430 RGA2460 RGA24120
4800 RGA4830 RGA4860