APC-SV4 and APC-SV8 Step Control Users Manual
Low Voltage Step Control with Vernier Stage (ver 1.02)
1 Ordering Code
APC-SV8 - Eight Position Step Control with Vernier
APC-SV4 - Four Position Step Control with Vernier
2 Description
The APC-SV8 is a microcontroller-based step controller that provides precise modulation in multi-stage heater applications such as duct heaters. The built-in Vernier stage allows for smooth, precision control of the load without increasing switching wear.
3 Key Features
-
Adjustable Stage Delay
-
Pulsed or Analog Vernier Output
-
Adjustable Vernier Ratio
-
Expandable to 16 stages
-
LIFO/FIFO Selection
-
Test Button
-
Brown Out Protection
4 Installation
WARNING: FIRE HAZARD!! Even quality electronic components CAN FAIL KEEPING FULL POWER ON! Provide a SEPARATE (redundant) OVER TEMPERATURE SHUTDOWN DEVICE to switch the power off if safe temperatures are exceeded.
WARNING: HIGH VOLTAGE!! This control is wired to a transformer, Solid State Relay, and contactors with high voltage on them. This control must be installed in a GROUNDED enclosure by a qualified electrician in accordance with applicable local and national codes including NEC and other applicable codes. Provide a safety interlock on the door to remove power before gaining access to the device.
4.1 Mounting Instructions/Dimensions
The APC-SV8 should be mounted using #6 screws at the five locations shown below. The board is supported by 5, 5/16" high spacers (supplied).
5 Dipswitch Settings
5.1 Input Selection
S1 positions 1-5, select which command input the APC-SV8 will accept.
OFF
Switch S1
Command Input
Pos 1
Pos 2
Pos 3
Pos 4
Pos 5
0-5V
0-10V*
2-10V*
4-20mA
0-135 OHM
mA
mA
10V
135R
135R
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
ON
ON
*If the 0-10V range is selected, the APC-SV8 will start responding with output just above 0V on the command input. If the 2-10V range is selected, the APC-SV8 will start responding with output just above 2V on the command input.
5.2 Stage Selection
S2 positions 1-4 select the number of output stages.
Switch S2
Output Stages
Pos 1
Pos 2
Pos 3
Pos 4
1
2
3
4
5
STP3
STP2
STP1
STP0
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
ON
ON
ON
6
7
8
9
10
11
12
13
14
15
16
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
OFF
ON
ON
ON
ON
OFF
OFF
OFF
ON
ON
OFF
OFF
ON
ON
OFF
OFF
ON
ON
ON
OFF
ON
ON
OFF
OFF
ON
ON
ON
OFF
ON
ON
ON
ON
ON
ON
ON
OFF
5.3 Output Mode Selection
LIFO (last in first out) and FIFO (first in first out) modes are both available by setting of S2 position 6.
LIFO/FIFO
SWITCH S2
Pos 6
LIFO
FIFO
FIFO
OFF
ON
LIFO mode is the normal default mode. In this mode the output stages respond like a level bar graph.
FIFO mode circulates the on stages to promote even use of the contactors and elements. For example, the first stage that was turned on when the power was increasing will be the first stage turned off when the power is decreasing.
5.4 Master/Slave Selection
S2 positions 5 selects master or slave operation.
Master/Slave
SWITCH S2
Pos 5
MASTER
SLAVE
SLV
OFF
ON
LIFO mode is the normal default mode. In this mode the output stages respond like a level bar graph.
FIFO mode circulates the on stages to promote even use of the contactors and elements. For example, the first stage that was turned on when the power was increasing will be the first stage turned off when the power is decreasing.