BOLEC ELECTRONICS / TECHNICAL PRODUCT GUIDE
SS501 Dual Channel Speed & RPM Switch
12/24 VDC · 2 inputs · 2 independent relay outputs · 2–9,990 Hz
bolec.com.au | sales@bolec.com.au | 0480 312 400 | Installation instructions Rev 12.7
Dual-channel speed protection
See the frequency. Set two thresholds. Control two outputs.
The SS501 combines an on-board digital display, a live frequency reader and two independently programmable relay channels in one Australian-made module.
- Read the selected channel’s live input frequency on the module
- Use two separate speed signals or one signal with two setpoints
- Compatible with magnetic pickups and Hall-effect sensors
- Normally open, normally closed and 1 Hz pulsing output modes
- Designed and manufactured in Australia
Why choose the SS501?
Live frequency, two setpoints and two outputs
A basic speed switch only reacts. The SS501 also shows the incoming frequency, lets the installer program two channels at the module and provides a separate relay action for each channel.
Check the live input frequency on-board
Press R to read the instantaneous frequency of the selected channel on the digital display.
Relay switching pauses while R is held.
Set HIGH and LOW thresholds at the module
Use the U, D and S controls to adjust and save switching points without changing the wiring.
Run two independent control jobs
Each channel has its own setpoints and volt-free output, configurable for N/O, N/C or 1 Hz pulsing operation.
Works across common speed-sensing applications
Accepts magnetic pickup or Hall-effect inputs from 2–9,990 Hz, with Channel 2 Hi-Res mode from 1–900 Hz.
Common applications
Flexible protection for engines and rotating equipment
Configure each channel independently to suit the machine, sensor and required action.
Alarm or shutdown
Operate a warning, interlock or shutdown circuit when speed rises above the programmed high setpoint.
Loss-of-speed detection
Use normally closed operation to release a solenoid or stop equipment after speed falls below the low setpoint.
Two actions from one signal
Connect one sensor signal to both channels for two independent switching points or output behaviours.
Technical specifications
Compatibility at a glance
Values below are taken from the SS501 Installation Instructions, Revision 12.7.
| Item | Specification |
|---|---|
| Supply | 12/24 VDC, negative ground; approximately 30 mA quiescent current |
| Inputs | 2 × inductive / magnetic pickup or Hall-effect sensor inputs |
| Frequency range | Channel 1: 2–9,990 Hz; Channel 2: 2–9,990 Hz |
| Channel 2 Hi-Res | 1–900 Hz in 1 Hz increments |
| Outputs | 2 × independent volt-free relay outputs |
| Relay rating | 5 A resistive at 12/24 VDC |
| Output modes | Normally open, normally closed or pulsing at 1 Hz |
| Enclosure | 76 × 29 × 100 mm deep; 84 mm mounting-hole centres |
Wiring
Eight-terminal connection map
Terminal numbering is viewed from the wire-entry side of the external connecting plug.
| Terminal | Function | Connection |
|---|---|---|
| 1 | Positive supply | Switched +12/24 VDC through a 3 A fuse |
| 2 | Channel 2 input | Speed or RPM signal |
| 3 | Negative / ground | Connect to a reliable ground point |
| 4 | Channel 1 input | Speed or RPM signal |
| 5 | Channel 1 output A | Volt-free relay contact; pair with terminal 7 |
| 6 | Channel 2 output A | Volt-free relay contact; pair with terminal 8 |
| 7 | Channel 1 output B | Volt-free relay contact; pair with terminal 5 |
| 8 | Channel 2 output B | Volt-free relay contact; pair with terminal 6 |
Important installation notes
Tie an unused input to ground. Fit flyback diodes across inductive loads, and unplug the SS501 completely before welding on the vehicle or machine.
Installation overview
Mount, wire, protect and program
- 1
Mount
Install in a protected location with the connector terminals pointing down.
- 2
Power
Supply terminal 1 through a 3 A fuse and connect terminal 3 to a sound ground.
- 3
Connect
Wire inputs to terminals 2 and 4, then use output pairs 5/7 and 6/8.
- 4
Program
Set the input level, high and low setpoints, and the required output modes.
Configuration
Open only the setting you need
Use this as a quick reference. The controlled installation manual takes precedence.
SW2: supply voltage and signal-level settings
SW2 selects supply voltage and high or low signal level for each input.
- Switch 1: OFF for 24 V, ON for 12 V
- Switch 2: Channel 1 signal level
- Switch 3: Channel 2 signal level
SW1: channel, setpoint and relay modes
SW1 selects the programming channel, setpoint, contact behaviour and pulsing mode.
- Return switch 1 to RUN after programming
- Switches 4–7 configure N/O, N/C and pulsing outputs
- Switch 8 enables Channel 2 Hi-Res mode
SET: program high and low setpoints
- Set SW2 for supply voltage and signal levels.
- Move SW1-1 to SETTING MODE.
- Select Channel 1 or 2, then HIGH or LOW.
- Adjust and press SET to save.
- Set LOW at least 5% below HIGH, then return SW1-1 to RUN.
RESET: relay behaviour and factory reset
N/O closes at HIGH and opens below LOW. N/C opens at HIGH and closes below LOW. Pulsing mode operates at 1 Hz above HIGH.
For a factory reset, hold SET while applying power and release it when the display reads rSEt.
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