Back-of-Module Temperature Sensor
The BOM-TS-485 is a PT1000 back-of-module temperature sensor that measures the rear-surface temperature of photovoltaic panels and reports it over RS-485 Modbus RTU, giving insight into panel performance across installations from small rooftop systems to utility-scale solar farms.
- Range
- -20 to +80°C
- Ingress
- IP65
- Supply
- 12-34 V AC/DC

Overview
In detail
How it works
A PT1000 1/3 Class B sensor (to EN 60751), built for flat surfaces, is mounted to the back of a solar panel and measures its surface temperature. Because PV panel efficiency is temperature-dependent, this reading feeds a fuller picture of panel performance.
The sensor housing is plastic with an aluminium mounting plate (12 x 50 x 50 mm), with overall sensor dimensions of 44 x 69 x 75 mm (H x W x L) and IP65 ingress protection. It connects via a 3 m or 5 m UV- and weather-resistant PUR cable.
Connectivity
Data is transmitted over a 2-wire RS-485 bus using the Modbus RTU protocol. Supported baud rates are 1200, 2400, 9600, 19200 and 38400, with none/even/odd parity and 1 or 2 stop bits (2 only at no parity). The factory default is 9600 baud, 8N1, at address 1.
Wiring is brown (power +), white (power -), green (RS-485 data + / A) and yellow (RS-485 data - / B).
Deployment
Suited to all sizes of PV solar installations, from small rooftop systems to utility-scale solar farms.
Reach out and say hi
Let us help. Tell us the site, the range you expect and what it has to talk to, and we’ll work out the right variant, cable and mounting — and quote it.
Specifications
Technical specifications
- Sensor type
- PT1000 1/3 Class B (EN 60751), for flat surfaces
- Range
- -20 to +80°C
- Accuracy
- ±0.1°C
- Supply voltage
- 12-34 V AC/DC
- Ingress
- IP65
- Housing
- Plastic housing with aluminium plate, 12 x 50 x 50 mm
- Dimensions
- 44 x 69 x 75 mm (H x W x L)
- Cable
- 3 m or 5 m PUR cable, UV and weather-resistant
- Protocol
- RS-485 Modbus RTU, 2-wire bus
- Communication rate
- 1200, 2400, 9600, 19200 or 38400 bps (default 9600)
- Parity
- None, even or odd
Ready to specify?
Add Back-of-Module Temperature Sensor to your enquiry
Build a list, add your site notes, and an ESS engineer will quote the lot — cables, mounting and calibration included.


