RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
- Messages
- 3,564
The only difference on the 368's for the btu unit sizing is the black start capacitor value. Larger btu unit have large value starter capacitor.
Roughly 4.5 uF for each 1k btu.
You don't have wide value selection options on black electrolytic caps because they have such poor value tolerances.
It takes a high bandwidth closed loop hall effect current sensor to a scope to measure the start-up current value and phase. Idea value is when start winding current is close to 90 degs phase from run winding current during startup period. During the start period the motor has much lower inductive reactive impedance. Because of the softstart triac ramp up you cannot measure this phase relations with Easystart. You have to temporarily put in a hardstart kit relay to measure phase and allow hardstart relay to release start cap after startup.
MicroAir table for the 366 bare PCB only model, no longer sold shown below, but the 368 x48k I bought had 124-189 uF cap in it which is slightly lower value.
Specifications/Notes
Roughly 4.5 uF for each 1k btu.
You don't have wide value selection options on black electrolytic caps because they have such poor value tolerances.
It takes a high bandwidth closed loop hall effect current sensor to a scope to measure the start-up current value and phase. Idea value is when start winding current is close to 90 degs phase from run winding current during startup period. During the start period the motor has much lower inductive reactive impedance. Because of the softstart triac ramp up you cannot measure this phase relations with Easystart. You have to temporarily put in a hardstart kit relay to measure phase and allow hardstart relay to release start cap after startup.
MicroAir table for the 366 bare PCB only model, no longer sold shown below, but the 368 x48k I bought had 124-189 uF cap in it which is slightly lower value.
Specifications/Notes
| IMPORTANT ADDITIONAL INFORMATION (for 366) Support Notice: Given its lower cost and higher complexity, Micro-Air will be unable to provide detailed technical support to DIY retail customers for single installations. Thank you for your understanding. Recommended Start Capacitors and Board Information. Capacitors 72-86MFD - Up to 12K BTU 88-106MFD - 13-23K BTU 108-130MFD - 24-36K BTU 189-227MFD - 37-48K BTU 270-324MFD - 49-72K BTU 115VAC applications can use 250V or 330V rated start capacitors. 230VAC applications must use 330V or 440V rated start capacitors. |
