Sharp EL-5500 III & PC-1403: Fan Laws and Voltage Drop Percentage
Fan Laws
The program will calculate RPM_new (Revolutions per Minute), SP_new (Static Pressure), and BHP_new (Brake Horsepower).
Inputs:
CFM_old: Cubic Feet of Minute - old
CFM_new: Cubic Feet of Minute - new
RPM_old: Revolutions per Minute - old
SP_old: Static Pressure - old
BHP_old: Brake Horsepower - old
Outputs:
RPM_new
SP_new
BHP_new
Sharp EL-5500III/PC-1403 Program: Fan Laws
RUN 700 (or whatever line you designate)
700 PRINT "FUN LAWS"
703 INPUT "CFM.OLD? "; A
706 INPUT "CFM.NEW? "; B
709 INPUT "RPM.OLD? "; C
712 INPUT "SP.OLD? "; E
715 INPUT "BHP.OLD? "; G
718 D = B*C/A
721 F = E*B^2/A^2
724 H = G*B^3/A^3
727 PRINT "RPM.NEW: "; D
730 PRINT "SP.NET: "; F
733 PRINT "BHP.NEW: "; H
736 END
Example
Inputs:
CFM.OLD: 1250 CFM
CFM.NEW: 1600 CFM
RPM.OLD: 840 RPM
SP.OLD: 4 in
BHP.OLD: 7 BHP
Results:
RPM.NEW: 1075.2 RPM
SP.NEW: 6.5536 in
BHP.OLD: 14.680064 BHP
Source:
Calculated Industries "Sheet Metal/HVAC Pro Calc User's Guide" 2021
Voltage Drop Percentage
This program calculates the voltage drop percentage for wires that operate in 75°C, given the wire length from the object to the power source for wires 2, 4, 6, 8, 10 and 12. The NEC 2020 code is used.
Sharp EL-5500III/PC-1403 Program: Voltage Drop Percentage
RUN 500 (or whatever line you designate)
500 PRINT "VOLTAGE DROP 75 DEG"
501 CLEAR
503 DIM S(5)
506 REM NEC 2020
509 S(0) = .194
510 S(1) = .308
511 S(2) = .491
512 S(3) = .778
513 S(4) = 1.24
514 S(5) = 1.98
530 INPUT "VOLTS? "; V
533 INPUT "CURRENT? "; A
536 INPUT "WIRE LGTH TO PWR (FT)? "; L
539 INPUT "#2,4,6,8,10,12? "; J
542 J = J/2 - 1
545 W = S(J)
548 D = (A*W/1000*2*L) / V * 100
551 PRINT "VD = "; D; "%"
554 END
Example
Inputs:
VOLTS: 80 V
CURRENT: 36 A
WIRE LGTH TO PWR (FT): 140 ft
#8 wire
Result:
VD = 9.8028%
Eddie
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