Belimo TRANE TAF Series, Technical Documentation Manual

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145
I20683 - Subject to change.
Wiring Guide
Basic Electricity
I. BASIC ELECTRICITY
I-A. Abbreviations
DC = Direct Current
AC = Alternating Current
VDC = Direct Current Voltage
VAC = Alternating Current Voltage
I-B. Current
A = Ampere
mA = Milliampere = Thousandths of an ampere. (Example: 12mA = 12/1000 = .012A)
I = The symbol for current in mathematical formulas.
I-C. Voltage
V = Volt*
mV = Millivolt = Thousandths of a volt. (Example: 5mV = 5/1000 = .005V)
E = The symbol for voltage in mathematical formulas.
I-D. Resistance
Ω
= Ohm = Resistance
k
Ω
= Kilo ohm = Thousands of ohms. 1k
Ω
= 1,000
Ω
M
Ω
= Mega ohm = Millions of ohms. 1M
Ω
= 1,000k
Ω
= 1,000,000
Ω
R = The symbol for resistance in mathematical formulas.
I-E. OHM's Law
E = Voltage I = Current R = Resistance
E = I x R Example: I = 20mA, R = 500
Ω
Therefore, E = .020 x 500 = 10V
R = E/I Example: E = 1.35V, I = 10mA Therefore, R = 1.35/.010 = 135
Ω
I = E/R Example: E = 120V, R = 50
Ω
Therefore, 120/50 = 2.4A
I-F. Power
W = Watt*
mW = Milliwatt = Thousandths of a watt (Example: 7mW = 7/1000 = .007W)
kW = Kilowatt = Thousands of watts (Example: 1kW = 1,000W)
I-G. Power Calculations
W = E x I Example: V = 24V, I = 260mA Therefore, W = 24 x .260 = 6.24W
W = R x I2 Example 1: R = 100
Ω
, I = 3A
W = 100 x 32 = 100 x 3 x 3 = 900W
Example 2: R = 500
Ω
, I = 20mA = .020A
W = 500 x .0202 = 500 x .020 x .020 = 500 x .0004 = .2W or 200mW.
W = E2/R Example: V = 24V, R = 100, Therefore, W = 242/100 = 24 x 24/100 = 5.76W
* I.S.O. standard indicates “U” be used for voltage and “P” for power.