3
SAFETY PRECAUTIONS
GENERAL:
Be sure to follow all applicable and prudent safety precautions when working with chemicals
and electrical equipment.
ELECTRICAL:
The circuit board and incoming A/C power line do include electrical shock risk. Take care
to avoid electrical shocks and do not touch any part of the circuit board or A/C power line unless you are certain
that A/C power has been disconnected from the system.
When connecting A/C power to the instrument, it is imperative that the A/C source be well grounded. Insuffi cient
A/C grounding will disrupt proper operation of the instrument.
CHECK FOR DAMAGE:
Before removing the product from the shipping packaging, carefully check the
equipment for damage. If any product is found damaged, do not put it into operation or install it. Contact
Hydro Instruments to discuss repair or replacement of the damaged equipment.
I. OVERVIEW
1.
Modes of the HC-220
– The HC-220 PID Controller has 2 modes that can be accessed. These modes are
as follows:
a.
Confi guration Mode – This mode is used to set up the control and display parameters. (Flow Meter
range, Control type, Display units, alarms, etc…)
b. Operation Mode – This is the mode used during operation of the HC-220 PID Controller. It allows for
Dosage and Set Point Adjustments as well as manual control of the chemical feed rate.
2.
Switching Between Modes
– The Confi guration Mode is password protected. The password is 220.
This can be entered by using the
and
buttons.
a. Operation Mode – This is the HC-220 standard mode. This can be reached from either of the other
two modes by repeatedly pressing the “up arrow”
key.
b.
Confi guration Mode – This mode is accessed from the Operation Mode by pressing the “down arrow”
key until the password screen is reached. Then enter the password “220” and then press the “down
arrow”
key.
3.
Menus & Display
– Within each “Mode” there is a set of “Parameters”. Parameters are represented by
the blocks in the following fl ow charts. To move between these parameters, use the “up arrow”
and
“down arrow”
keys.
4.
Control Methods
– The HC-220 offers four different control methods. They are Flow Pacing (Propor-
tional), Residual/ORP, Compound Loop Control, and Manual Control. The method is selected within the
“Confi guration Mode”. (See Section III.)
5.
Electrical Inputs
– The HC-220 offers two analog input channels standard. The PV1 input channel is
used only for a Flow (e.g. proportional) signal. The PV2 input channel is used only for a Residual (e.g.
set point) signal. A third, optional analog input is sometimes included. The optional PV3 input channel is
used only for remote adjustment of the Set Point setting. Each channel can be set to accept either 4-20mA
or Modbus RS-485 signals. Each of the process variable inputs are individually selectable to be read over
any of the four analog input channels AI1, AI2, AI3, or AI4 and also over Modbus.
