Controller 1
C1050 RTU
Controller 2
C1050 Water Loop
Supply
24 VAC, Class 2
Relays
17A @ 277 VAC
Protocol
Modbus RTU (RS485)
Panel
NEMA 1, UL listed
Overview
The Prolon PL-PN2-4M-4Q is a pre-wired, UL listed NEMA 1 two controller panel built with a Prolon C1050 Zoning Rooftop Controller and a Prolon C1050 Water Loop Controller. Isolation relays rated 17A @ 277 VAC on all digital outputs, overcurrent fuse protection and clearly marked terminal blocks come factory wired.
The C1050 Zoning Rooftop Controller operates rooftops or other mechanical HVAC systems, and acts as a master when used on a network with other Prolon zone controllers. The C1050 Water Loop Controller controls a water loop system comprised of a boiler and a water tower with an internal pump. The panel contains 2 Modbus RTU (RS485) nodes and runs stand-alone or on a Prolon network of up to 127 nodes.
Specifications per Prolon Pre-Wired Two Controller Panel datasheet PL-DATA-PANEL2CON-EN-V1; Prolon PL-C1050-RTU Controller datasheet REV 7.3.0 / PL-DATA-C1050RTU-C/F-EN; Prolon PL-C1050-WLC Controller datasheet REV 7.3.1 / PL-DATA-C1050WLC-C/F-EN; Prolon C1050 Rooftop Controller Hardware Guide (RTU and RTUS) REV 7.3.3; Prolon C1050 Water Loop Controller Hardware Guide REV 7.3.2; Prolon Two Controller Panel product page (proloncontrols.com) retrieved 2026-09-24. Reviewed September 2026.
Best For
- Zoned rooftop units with Prolon zone controllers
- Water loops served by a boiler and a water tower
- Mechanical rooms where two controllers share one UL listed enclosure
Warranty
For warranty coverage on this Prolon panel, contact ZOT Supply at sales@zotsupply.com or 855-825-2811.
Key Features
Two independent controllers
Controllers need not be related in function and may each serve completely different sequences from separate power sources.
17A isolation relays
Every digital output is isolated by a relay rated 17A @ 277 VAC built into the panel (C1050 = 4, M2000 = 5), and the controller outputs are protected by resettable fuses.
Fused, pre-wired NEMA 1 panel
Clearly marked terminal blocks, wire management channels and a disconnect-style Slo-Blo fuse (3A @ 250 VAC) with a replacement fuse included. The wiring diagram is in the door, and all inputs and outputs are tested in the factory.
C1050: Zoning master
Acts as the master on a network of Prolon zone controllers, with zone weighting and network demand strategies.
C1050: Heat and reject on one loop
Output 1 drives the boiler, and outputs 2 to 5 open the tower damper, run the spray pump and stage the cooling tower.
Reflash to another program
Each controller keeps its full functionality, including the ability to reflash into a different controller program. Wiring diagrams are available free at proloncontrols.com.
ZOT Supply is an authorized distributor of Prolon products.
Technical Specifications
| Panel | |
|---|---|
| Controllers | Prolon C1050, Zoning Rooftop Controller program + Prolon C1050, Water Loop Controller program |
| Supply | 24 VAC ±10%, 50/60 Hz, Class 2 |
| Overcurrent Protection | Disconnect-style Slo-Blo fuse (3A @ 250 VAC), with additional replacement fuse included |
| Enclosure | NEMA 1 |
| Panel Dimensions | 16.25 in. W x 20.25 in. H x 6.25 in. D (413 mm W x 514 mm H x 159 mm D) |
| Weight | 38 lbs (17.25 kg) |
| Isolation Relays | 17A @ 277 VAC on all digital outputs (C1050 = 4, M2000 = 5) |
| Network Nodes | Stand-alone or networked (up to 127 nodes); this panel contains 2 nodes |
| Environment | -4 to 122 °F (-20 to 50 °C), non-condensing |
| Panel Certification | Complete panel is UL certified |
| Certification | UL916 Energy Management Equipment, CAN/CSA-C22.2, RoHS, FCC part 15: 2012 class B |
| C1050 Controller Hardware | |
| Power | 2 VA (consumption), 32 VA (input) |
| Inputs | Outdoor: thermistor 10K; Return: thermistor 10K; Supply: thermistor 10K; External clock or Proof of fan: dry contact |
| Digital Outputs | 4 triac outputs, 10-30 VAC source or sink, 300 mA max (resettable fuse) |
| Analog Outputs | 1 output 0-10 VDC / 2-10 VDC / 0-5 VDC, 40 mA max (resettable fuse) |
| Indication Lights (LED) | State of each output / Communication / Power / State of microprocessor |
| Casing | Molded ABS, UL94-HB |
| Communication | Modbus RTU (RS485) up to 127 nodes |
| Baud Rates | 9600, 19200, 38400, 57600, 76800, 115200 |
| Connection | Removable screw-type terminal blocks (max 16 AWG) |
| Zoning Rooftop Controller Program | |
| Program | Zoning Rooftop Controller |
| Application | Operates rooftops or other mechanical HVAC systems, and acts as a master when used on a network with other Prolon zone controllers |
| Program Inputs | Outdoor, return and supply: 10K thermistor; external clock or proof of fan: dry contact |
| Program Outputs | 4 triac outputs, all set to SOURCE mode because they share a single source supply (the equipment transformer); analog output: 1 output 0-10 VDC / 2-10 VDC / 0-5 VDC |
| C1050 Controller Hardware | |
| Power | 2 VA (consumption), 32 VA (input) |
| Inputs | Supply water temp: thermistor 10K; Return water temp: thermistor 10K; Auxiliary temp: thermistor 10K; Auxiliary digital input: dry contact |
| Digital Outputs | 4 triac outputs, 10-30 VAC source or dry contact, 300 mA max (resettable fuse) |
| Analog Outputs | 1 output 0-10 VDC, 40 mA max (resettable fuse) |
| Indication Lights (LED) | State of each output / Communication / Power / State of microprocessor |
| Casing | Molded ABS, UL94-HB |
| Communication | Modbus RTU (RS485), up to 127 nodes |
| Baud Rates | 9600, 19200, 38400, 57600, 76800, 115200 |
| Connection | Removable screw-type terminal blocks (max 16 AWG) |
| Water Loop Controller Program | |
| Program | Water Loop Controller |
| Application | Controls a water loop system comprised of a boiler and a water tower with an internal pump |
| Program Inputs | Supply water, return water and auxiliary temp: 10K thermistor; auxiliary digital input: dry contact |
| Program Outputs | 4 triac outputs, each SOURCE (active) or SINK (passive, isolated dry contact) by on-board switch, 300 mA max (resettable fuse); output 1 heating (boiler); outputs 2 to 5 cooling actions (tower damper or bypass valve, spray pump, tower stage 1, tower stage 2); analog output 0-10 VDC, 40 mA max (resettable fuse) |
Documentation
Frequently Asked Questions
What is the Prolon PL-PN2-4M-4Q?
A pre-wired two controller panel built with a Prolon C1050 Zoning Rooftop Controller and a Prolon C1050 Water Loop Controller, in a UL listed NEMA 1 enclosure with 17A isolation relays on all digital outputs.
What does the C1050 zoning rooftop program control?
It operates rooftops or other mechanical HVAC systems, and acts as a master when used on a network with other Prolon zone controllers. Strategies include unoccupied mode settings, morning warm-up and supply air pre-heating and zone weight and network demand control strategy.
What does the C1050 water loop program control?
It controls a water loop system comprised of a boiler and a water tower with an internal pump. Strategies include bypass valve control, cooling tower damper control and spray pump and cooling tower staging.
What power does the panel require?
24 VAC ±10%, 50/60 Hz, Class 2; each C1050 draws 2 VA (consumption), 32 VA (input).
Can the two controllers serve different equipment?
Yes. The controllers need not be related in function and may each serve completely different sequences from separate power sources.
Are the outputs isolated and protected?
Yes. Every digital output is isolated by a relay rated 17A @ 277 VAC built into the panel, and the panel has a disconnect-style Slo-Blo fuse (3A @ 250 VAC) with a replacement fuse included.
What size is the PL-PN2-4M-4Q panel?
16.25 in. W x 20.25 in. H x 6.25 in. D (413 mm W x 514 mm H x 159 mm D), and it weighs 38 lbs (17.25 kg).
How are the C1050 digital outputs wired?
On the C1050 rooftop program, all triac outputs are set to SOURCE mode because they share a single source supply, the equipment transformer.
- Panel Type:
- Dual Controller Panel
- Display:
- No Display
- Controller Type:
- Rooftop
- Controller Type:
- Water Loop
- Communication:
- Modbus RTU (RS485)
