Controller 1
C1050 FCU
Controller 2
C1050 FlexIO
Supply
24 VAC, Class 2
Relays
17A @ 277 VAC
Protocol
Modbus RTU (RS485)
Panel
NEMA 1, UL listed
Overview
The Prolon PL-PN2-4E-4F is a pre-wired, UL listed NEMA 1 two controller panel built with a Prolon C1050 Fan Coil Unit Controller and a Prolon C1050 FlexIO Controller. Isolation relays rated 17A @ 277 VAC on all digital outputs, overcurrent fuse protection and clearly marked terminal blocks come factory wired.
The C1050 Fan Coil Unit Controller operates two-pipe or four-pipe hydronic fan coil systems using PI (proportional-integral) control loops. The C1050 FlexIO Controller is a general purpose HVAC controller whose inputs and outputs can be individually configured for applications not covered by a dedicated Prolon program. 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-FCU Controller datasheet REV 7.4.0 / PL-DATA-C1050FCU-C/F-EN; Prolon PL-C1050-FLX Controller datasheet REV 7.3.0 / PL-DATA-C1050FLX-C/F-EN; Prolon C1050 Fan Coil Controller Hardware Guide REV 7.4.1; Prolon C1050 FlexIO Controller Hardware Guide REV 7.3.2; Prolon Two Controller Panel product page (proloncontrols.com) retrieved 2026-09-24. Reviewed September 2026.
Best For
- Two-pipe fan coils with automatic changeover
- Outlying HVAC functions not covered by a dedicated Prolon program
- 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: Two-pipe or four-pipe
Supports on-off and modulating valves in two-pipe or four-pipe configurations, with automatic changeover and purge cycles.
C1050: Up to 5 occupancy states
Can receive up to 5 different occupancy states from an NC2000, and outputs can act on any local input or on network data.
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, Fan Coil Unit Controller program + Prolon C1050, FlexIO 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 Air Temp / Supply Air Temp / Supply Water Temp / dry contact for proof of fan or leak alarm |
| Digital Outputs | 4 triac outputs, 10-30 VAC source or sink, 300 mA max (self-resetting fuse) |
| Analog Outputs | 1 output 0-10 VDC / 2-10 VDC / 0-5 VDC, 40 mA max (self-resetting 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) |
| Fan Coil Unit Controller Program | |
| Program | Fan Coil Unit Controller |
| Application | Operates two-pipe or four-pipe hydronic fan coil systems using PI (proportional-integral) control loops |
| Program Inputs | Outside air, supply water and supply air: 10K thermistor; proof of fan / alarm: dry contact |
| Program Outputs | 4 triac outputs; analog output: 1 output 0-10 VDC / 2-10 VDC / 0-5 VDC for the valve |
| C1050 Controller Hardware | |
| Power | 2 VA (consumption), 32 VA (input) |
| Inputs | 3 analog inputs with individually configurable signal ranges (thermistor, dry contact, 0-5 VDC, 1-5 VDC, 0.5-4.5 VDC, 0-10 VDC), and 1 digital input |
| 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 (16 AWG max) |
| FlexIO Controller Program | |
| Program | FlexIO Controller |
| Application | Is a general purpose HVAC controller whose inputs and outputs can be individually configured for applications not covered by a dedicated Prolon program |
| Program Outputs | 4 triac outputs; analog output: 1 output 0-10 VDC / 2-10 VDC / 0-5 VDC |
Documentation
Frequently Asked Questions
What is the Prolon PL-PN2-4E-4F?
A pre-wired two controller panel built with a Prolon C1050 Fan Coil Unit Controller and a Prolon C1050 FlexIO Controller, in a UL listed NEMA 1 enclosure with 17A isolation relays on all digital outputs.
What does the C1050 fan coil unit program control?
It operates two-pipe or four-pipe hydronic fan coil systems using PI (proportional-integral) control loops. Strategies include two-pipe automatic mode change based on supply water temperature, periodic purge cycles and secondary backup heat control.
What does the C1050 flexio program control?
It is a general purpose HVAC controller whose inputs and outputs can be individually configured for applications not covered by a dedicated Prolon program. Strategies include ON/OFF, PI loop, direct or reverse acting, and pulsed output logic, output interlocks and overrides based on outside temperature and/or occupancy.
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-PN2-4E-4F 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).
- Panel Type:
- Dual Controller Panel
- Display:
- No Display
- Controller Type:
- Fan Coil
- Controller Type:
- FlexIO
- Communication:
- Modbus RTU (RS485)
