ZK Type SCR Voltage Regulator

1. Introduction

ZK type SCR voltage regulator is used with SCR, it can adjust the load heating power, phase-shifting triggering mode have  depth voltage negative feedback, so it has a good adjustment linear, the impact of network fluctuating will be the smallest. Zero-crossing triggering mode’s instrument design have network voltage fluctuation compensation function, it can stabilize different power voltage heating power

2. Characteristics

2.1  Design newly,on the plane built-in big ammeter is for output indication, legible to read and adjust the machine to zero. The instrument’s depth cut normal production down to half than, weight lighten 2kg, shock-resistant feature is good,anti-jamming ability is strong.

2.2 When load is short circuit or overcurrent,the instrument can close automatically SCR’s  trigger signal in 1~2 period,let SCR carry current and protect from damage,at the same time it have indication function when load is short circuit.

2.3 Directly get synchronizing signals from the network, applies to the  ” Y ” method connection,  control is stable and reliable.

3. Model explanation: ZK type SCR voltage (average power ) regulator

Size unit( mm)           Exterior size       Install size              Exterior size        Install size

  Single phase voltage regulator ZK-1:160×80×130; 152×76; ZKA-1:96×96×130; 92×92   

Three phases voltage regulator  ZK-3:160×80×130;152×76; ZKA-3:96×96×130; 92×92  

4. Main technical indicators

4.1 Input signal:0~10mA(Input Impedance 800Ω)or 4~20mA(Input Impedance 250Ω);

4.2 Output pulse:Amplitude value is not less than 3V、Width is not less than 50uS (20Ω load);

4.3 Phase – shift trigger maximum conduction angle:not less than 150°;

4.4 Working environment:

Temperature: 0~50℃,relative humidity≤85%,without corrode and strong electric radiation;

4.5 Power supply:AC220V±15%, 50Hz about 3VA

4.6 Weight:about 0.8Kg

5. Installation

5.1 Inspect the instrument accessories:two mounting screws、two mounting boards;

5.2 Connect input、output(SCR control electrode’s G1、G2 and K)1、K2)、feedback、power、ground and furnace wires according to the specification.

5.3 When adopt “Y” method connection,SCR’s resist pressure must be over 600V. SCR’s rated current must be more than  1.5 times of practical using electric currents. SCR must be used with  radiator of area big enough, and pay attention to air ventilation,assure that SCR’s temperature does not excees120℃ under any condition. When control method is  half-controlled, diode’s resist pressure、current index are as single phase SCR.

5.4 Three fuses  (connected serially SCR’s anode ) need connect phase line input terminal, and shall not connect other locations.

5.5 If the SCR’s radiator is alive, when install, you  should give full consideration to prevent getting an electric shock and short circuit between SCR.

5.6 If connect amperemeter, you must connect serially SCR’s anode, don’t let the trigger signal move through amperemeter.

5.7 Every SCR’s trigger signal line and other wires should be separate wiring, prevent interfereing with each other and lead to  SCR trigger losing control.

6.Operating and Adjusting

6.1  Put the  ”manual ~ automatic” toggle switch to the  ”manual” position,  turn counterclockwise the ” manual regulation” spin on the panel, plugged in the power switch, the power indicator light is light switch, the instrument can work.

6.2  Adjust the ” manual regulation” spin on the panel, reflecting furnace heating voltage ammeter reading will increase from 0 to 90% about, then decrease the ammeter reading to 40% about, wait a moment, the furnace temperature increase, it means that the instrument manual work normally.

6.3  If the instrument cooperate with the meter having current output P.I.D adjusting,put the  ”manual ~ automatic” toggle switch to the “automatic” position, the load heating voltage is automatically controlled P.I.D adjusting meter’s output current value. 

6.4  Put the  ”manual ~ automatic” toggle switch to the  ”manual” position, adjust the ” manual regulation” spin, heating voltage is adjusted to the needed value,at the moment the instrument’s function is like a manual voltage regulator.

6.5 If load design heating power is large, or low temperature  low internal impedance object initial heat, you can limit the maximum heating power by adjusting the “feedback” potentiometer on the panel,at the moment indicate output ammeter reading diminish,it can protect load or SCR from being damaged in the current. In general conditions, put the instrument to  the “automatic” function, when full input(if 10mA), adjust the “feedback” potentiometer again, let load voltage value subject to 90% of supply voltage.

6.6 Don’t drive inductive load, such as induction furnace、step-down transformer,  avoid SCR damage.

6.7 If a phase SCR can not full conduct or output serious shake, you can exchange the phase  trigger signal output connection.

6.8 The instrument’s all internal adjustment potentiometer have been transferred before leaving factory, in general conditions, don’t transfer random.

7. Wiring diagramconsult):


ZK-1 two-way SCR phase-shifting triggering                       ZK-1one way SCR phase-shifting triggering


ZK-3 two-way SCR phase-shifting triggering

In order to prevent SCR from moment high voltage breakdown, resistance R and capacitance C are RC absorb network circuit, R is 1.5Ω/0.5W Carbon-Film resistor, C is 0.1μf/630VAC non-inductively polyacrylamide capacitance.