Introduction to Wiring Diagrams
This manual provides wiring diagrams for Modine HER, VE, and PTE series electric unit heaters. Two types of diagrams are included for each circuit configuration: a connection diagram for field installation and a circuit schematic for continuity and troubleshooting.
Solid lines in the diagrams indicate factory pre-wiring, while dotted lines show connections required for the unit to operate. It is crucial that all wiring complies with the National Electrical Code, local codes, and that all components are compatible with their respective power sources.
Wiring Diagram Selection
Diagrams are identified in the Page Location Index (Table 2.2). To select the correct wiring diagram, follow these steps:
- Determine the unit heater model and size.
- Select the appropriate power code number from Table 2.1 based on the power supply (Volts/Phase).
- Reference the unit heater model and power code in the Page Location Index (Table 2.2) to find the corresponding wiring diagram page number.
Safety Precautions
CAUTION: Turn off all power to the unit before wiring. Failure to wire this unit according to this wiring diagram may result in injury to the installer or user. For deviations, contact the factory.
Abbreviations and Symbols
The following abbreviations and symbols are used for clarity, as recommended by ANSI and NEMA standards:
| Abbreviation/Symbol | Description |
|---|---|
| XFMR or TR | Transformer |
| V | Volts |
| Hz | Cycle or Hertz |
| [Phase Symbol] | Phase |
| LC | Limit Control |
| THERM or TH | Thermostat |
| G | Ground |
| HTR | Heater |
| H | Hot or High |
| SW | Switch |
| C | Common |
| "J" Box | Junction Box |
| L | Low |
| H1, H2, etc. | Transformer Primary Terminals |
| O.L.C. | Overload Contact |
| R | Relay |
| Rc | Relay Contact |
| VA | Volt-Ampere |
| X1,X2, etc. | Transformer Secondary Terminals |
| L1, L2, etc. | Electric Load Terminals |
| T1, T2, etc. | Starter or Motor Terminals |
Wire Color Coding
The following wire color codes are used:
| Color Code | Color Name |
|---|---|
| BK | Black |
| BU | Blue |
| R | Red |
| W | White |
| Y | Yellow |
Additional wire color codes:
| Wire Code | Color Name |
|---|---|
| BK | Black |
| BL | Blue |
| R | Red |
| W | White |
| Y | Yellow |
| X1,X2, etc. | Transformer Secondary Terminals |
| L1, L2, etc. | Electric Load Terminals |
| T1, T2, etc. | Starter or Motor Terminals |
Model and Power Code Information
Table 2.1: Power Code Selection
| Power Code | Power Supply (Volts/Phase) | |||||
|---|---|---|---|---|---|---|
| 208V/1 | 240V/1 | 208V/3 | 240V/3 | 480V/3 | 600V/3 | |
| 11 | X | |||||
| 12 | X | |||||
| 31 | X | |||||
| 32 | X | |||||
| 33 | X | |||||
| 34 | X | |||||
Table 2.2: Electric Unit Heater Page Location Index
| Model No. | Power Code | |||||
|---|---|---|---|---|---|---|
| 11 | 12 | 31 | 32 | 33 | 34 | |
| HER 30 | 3 | 3 | 5 | 5 | 8 | 9 |
| HER 50 | 3 | 3 | 5 | 5 | 8 | 9 |
| HER 75 | 3 | 3 | 5 | 5 | 8 | 9 |
| HER100 | 4 | 4 | 5 | 5 | 8 | 9 |
| HER125 | - | - | 5 | 5 | 8 | 9 |
| HER150 | - | - | 6 | 5 | 8 | 9 |
| HER200 | - | - | 7 | 7 | 8 | 9 |
| HER250 | - | - | 7 | 7 | 8 | 9 |
| VE 50 | - | 10 | 11 | 11 | 12 | - |
| VE 75 | - | 10 | 11 | 11 | 12 | - |
| VE100 | - | 10 | 11 | 11 | 12 | - |
| VE150 | - | - | 14 | 14 | 15 | - |
| VE200 | - | - | - | 14 | 15 | - |
| VE250 | - | - | - | - | 15 | - |
| VE300 | - | - | - | - | 13 | - |
| VE400 | - | - | - | - | 13 | - |
| VE500 | - | - | - | - | 13 | - |
| PTE300 | - | - | - | - | 13 | - |
| PTE400 | - | - | - | - | 13 | - |
| PTE500 | - | - | - | - | 13 | - |
Wiring Diagram Details
The following sections describe the wiring diagrams available for different Modine unit heater models, voltage, and phase configurations.
Diagrams for Modine HER Series Unit Heaters
Page 3: Wiring Diagram Model HER, 208V or 240V, single-phase power supply, 3kW, 5kW, 7.5kW Horizontal Models. Shows electrical supply, fused disconnect, power terminal block, limit control, electric heat contactor, fan motor, and heating elements (parallel wired).
Page 4: Wiring Diagram Model HER, 208V or 240V, single-phase power supply, 10kW Horizontal Model. Similar to Page 3 but for 10kW models.
Page 5: Wiring Diagram Model HER, 208V or 240V, three-phase power supply, 3kW, 5kW, 7.5kW, 10kW, 12.5kW, 15kW (240 only) Horizontal Models. Depicts wiring for three-phase supply with heating elements wired in a delta configuration.
Page 6: Wiring Diagram Model HER, 208V, three-phase power supply, 15kW Horizontal Model. Specific diagram for 15kW, 208V, three-phase HER models.
Page 7: Wiring Diagram Model HER, 208V or 240V, three-phase power supply, 20kW, 25kW Horizontal Models. Details wiring for higher capacity three-phase HER units.
Page 8: Wiring Diagram Model HER, 480V, three-phase power supply, 3kW to 25kW Horizontal Models. Covers diagrams for 480V three-phase HER units, including transformer connections for voltage step-down.
Page 9: Wiring Diagram Model HER, 600V, three-phase power supply, 3kW to 25kW Horizontal Models. Details wiring for 600V three-phase HER units, including transformer connections.
Diagrams for Modine VE and PTE Series Unit Heaters
Page 10: Wiring Diagram Model VE, 240V, single-phase power supply, 5kW, 7.5kW, 10kW Vertical Models. Includes a general schematic overview and detailed wiring for power junction box, control terminal block, fan motor, contactor, limit control, and heating elements.
Page 11: Wiring Diagram Model VE, 208V or 240V, three-phase power supply, 5kW, 7.5kW, 10kW Vertical Models. Shows three-phase wiring for VE models.
Page 12: Wiring Diagram Model VE, 480V or 600V, three-phase power supply, 5kW, 7.5kW, 10kW Vertical Models. Details wiring for 480V/600V three-phase VE models, including transformer junction box.
Page 13: Wiring Diagram Model VE, PTE, 480V or 600V, three-phase power supply, 30kW, 40kW, 50kW Vertical and Power Throw Models. Covers high-capacity three-phase VE and PTE units with two-stage thermostats and multiple contactors.
Page 14: Wiring Diagram Model VE, 208V or 240V, three-phase power supply, 15kW, 20kW Vertical Models. Specific diagrams for 15kW and 20kW three-phase VE units.
Page 15: Wiring Diagram Model VE, 480V or 600V, three-phase power supply, 15kW, 20kW, 25kW Vertical Models. Details wiring for 480V/600V three-phase VE units with time delay relays.
Company Information
For SERVICE, contact your local qualified installation and service contractor or appropriate utility company.
Modine Manufacturing Company has a continuous product improvement program and reserves the right to change design and specifications without notice.
Modine Manufacturing Company • 1500 DeKoven Avenue • Racine, Wisconsin 53403-2552
Tel: 1.800.828.4328 (HEAT) • www.modine.com
© Modine Manufacturing Company 2020
