Tempco TEC-9300, Инструкция по эксплуатации, Страница: 51 / 92

47
5–1 Pump/Pressure Control
Regulated water supply systems are widely used in residential
areas, water plants, chemical plants, electrical plants, semicon-
ductor plants, etc. By taking advantage of its PUMP function, the
TEC-9300 can be used to create an economical yet versatile solu-
tion for these applications. Here is an example:
The water pressure in this example must be controlled at
10Kg/cm≈. To achieve this, the following devices are used for
this example:
Inverter:
To supply a variable frequency AC voltage to the
motor.
Motor: A 3-Ø induction motor.
Pump: Any appropriate economical type of pump.
Pressure Sensor: A three-wire or two-wire type of pressure
transducer with a 0–20Kg/cm≈ range.
Pressure Reservoir:
Provides smoother pressure for the
system.
TEC-9300: Order a TEC-9300 with standard input, 4–20mA
output 1, 20V DC output 2 for sensor power.
Set the following parameters in the setup menu:
Adjust the following parameters
in the user menu:
A1SP: optional
REFC = 3
PB1 = 10.00
TI1 = 1
TD1 = 0.2
SP2 = -0.50
PL1 = 100
Refer to section
4-12 for more
details.
FUNC = FULL
COMM: optional
IN1 = 4-20
IN1U = PU
DP1 = 2-DP
IN1L = 0
IN1H = 20.00
IN2 = NONE
OUT1 = REVR
O1TY = 4-20
O1FT = 0
OUT2 = DCPS
A1FN: optional
EIFN = NONE
PVMD = PV1
FILT = 1
SELF = NONE
SLEP = NONE
SPMD = PUMP
SP1L = 5.00
SP1H = 15.00
SP2F = DEVI
Chapter 5 Applications
Key menu:
SPMD
SP2F
REFC
SP2
5–2 Variable Period Full Wave SSR
(VPFW SSR)
VPFW SSR is a variable period full wave solid-state relay. It can
provide a zero cross output with superior controllability com-
pared to a conventional SSR with a fixed time base. The block
diagram of VPFW SSR is shown as follows:
Unlike a conventional SSR, the VPFW SSR always gives the out-
put an even number of half cycles (full wave) as shown in the fol-
lowing diagram.
The VPFW switches the load without DC current, minimizing the
harmonic current and stress on the load. This prolongs the load
life.
Since the duty cycle (i.e., output power level) of the control input
is small, the off-period will be extended to keep the output reso-
lution such that the conversion error is minimized. As low as
0.1% timing error can be achieved. Hence, VPFW SSR is partic-
ularly suitable for smoother control.
Figure 5.2
Block Diagram of VPFW SSR
NOTES:
1. The VPFW SSR can be used to drive a resistant load and some
types of inductance loads such as relay, contactor, magnetic
switch, solenoid valve, etc. However, it can not drive a motor
or capacitance load .
2. Only AC power can supply VPFW SSR, otherwise it will not
operate properly.