Welcome to our
This month our
Product Category Focus
SSRs, LED DImmers,
AC - DC Logic Level Shifters, Relays, Contactors, Thyristors
& IGBT Proportional Control, Soft Starters, 1> 3 Phase
Soft Motor Starters, AC Voltage Stabilisers, AC Voltage Optimisers,
Variacs and Transformers.
All Single Phase
and many Three Phase products.
So a big mouth
full. again.13 companies.
SSRS - ( AC & DC Solid State Relays )
OPTO 22 invented
Optically Coupled SSRs back in the early 1970s. SCRs and Triacs
were quite new as technology back then and OPTO 22 glued in an
optical barrier and made them controllable safely. They are still
the leaders in this field.
thousand OPTO 22 products have been sold into the NZ Market over
the intervening years.
SSRs have huge
advantages over Contact Relays in that they don't arc out or
wear out. They usually drop the load on AC Voltage zero crossing
once the control voltage is zero.
( The control voltages are either DC 3-32 VDC or AC 14-280 VAC
SSRs also offer
4000VAC isolation between the load side and the control side,
so they offer great safety when switching high voltages with
Control gear like PLCs, PACs and PC IO.
have huge surge current ability, typically 10-20 times operating
current, so excellent for inductive loads like machine motors,
compressors, refrig etc
SSRs come in
many form factor and mountings, Bare Bones plate, Heat Sink,
PCB, DIN Rail and various Backplane configurations.
The only down
side of SSRs.
They require a minimum voltage to turn on
( typ 1.6VAC)
They have small Off State leakagecurrent.
( typ 7-15 mAs)
This means you
can not use them as a general switch like a contact relay, they
must be in-circuit with a load.
There are also
DC SSRs and these come in similar form factors as AC SSRs and
have Isolation etc but just switch DC Loads. These can be from
just a few amps and volts right up to 100Amps and 400VDC etc.
Basically a giant optically coupled FET.
Logic Level Shifters
( AC and
DC Models )
OPTO 22 also
invented what I call Logic Level Shifters. Opto 22 calls them
Input and Output Modules.
A Logic Level
Shifter or IO module from OPTO 22 and others works like this.
They take a High Voltage AC 230VAC Logic Level and converts it
down to to a Low Logic level ( 5, 15 or 24 VDC )
take say 110VDC converted to 5, 15 or 24VDC Logic Levels.
This can be done
with resistors and diodes and caps etc but these modules are
a generalised tough industrial solution.
The main advantage
these devices have over a resistor, diode, cap system is that
between the two voltage levels, an Optical Barrier exists, good
to 4000 VAC. Again, a great way to protect control gear from
damaging high voltage levels by safely converting them down in
a safe way to get logic levels control device can use.
Many PLC installers place a large
bank of these Logic Level Shifters between the PLCs Inputs and
the high voltage they are monitoring. There is no point in damaging
or destroying very expensive PLCs inputs. The cost of these barriers
is very low in comparison.
In Opto 22 PACs, all their input
and output modules have Isolation barreirs. This means you can
safely wire 230VAC directly to the PAC without worry.
Another very popular thing that
OPTO 22 introduced was to use colour coding on their modules
and the whole world has copied this.
So for instance, if you have
a DIN Rail full of Power IO DIN SSRs and Logic Level Input Modules,
you can tell at a glance which module type is which by colour.
Black is an output AC SSR
Red is an output DC SSR
Yellow is an input AC Level Shifter.
White is an input DC Level Shifter
OPTO 22 also
has a great product here.
Relays and Contactors
We have all the way from Reed
Relays to large Industrial Grade Contactors, single or three
IGBT Prportional Controllers
These are used on Electric Heating
systems ( furnaces ) mainly.
CD Automation, Jumo & AEG are specialists.
CD Automation make some of the
best three phase soft starters. They have 3 wire and 6 wire starters
with currents to 165 amps. Check these if you are having difficulty
with your present starters.
1 Phase to Three
Phase Soft Starters
Fastec starters and 1 to 3 phase
converter modules are a technology jump in this special area.
Check this if you have any products requiring three phase to
5KWs but only have single phase at the site.
Meat Grinders, Workshop Machinery, Car Stackers, Compressors,
Refrig Systems, and Submersible Pumps. Fans, Sump Pumps etc
These Fastec Modules can be controlled
by a switch or a PLC, PAC or Discrete Controller.
IREM and Belotti are the world
leaders in Variacs. Single and Three Phase units, hand control,
motorised & servo control.
Up until this newsletter, MasTec
has always lumped Automatic Voltage Regulator products in to
However we have now rectified
our faulty thinking and have made Line Conditioners as a seperate
category. Line Conditioners typically remove noise, spikes and
surges from AC and DC lines.
AVR systems are a different kettle
of fish and we have two types, but basically the same thing but
All AVRS have a set point to
control to. In the case of NZ AVRs that would be 230 VAC Single
Phase / 400 VAC three phase. An AVR Stabiliser will endeavour
to keep the output voltage at these levels.
An AVR Optimiser has a variable
set point for control and typically that setpoint is 210 to 220
VAC to reduce currents, lengthen light bulbs lives etc.The purpose
of the optimiser is to reduce power consumption and lenghten
infrastrucutre product lives.
Both Belotti & IREM make
a broad range of Voltage Optimizers and Stabilizers for energy
savings, somtimes up to 40%.
Optimizers reduce the mains voltage
to the lowest level of the AC Mains range and holding it there.
These devices comply with the requirements of IEC 60038 for electric
equipment operating tolerances and supply an operating voltage
which minimises consumption without impairing performance or
reducing reliability, applies to lighting and motors.
Both types use IGBT Patented
Technology or Servo controls driving Autotransformer Variacs
to stabilise mains variations and set them at a level designated
by the operator.
IREM, TrippLite and Belotti for
Industrial and Medical Transformers single & three phase.