Advice for the Mobile and Seasonal RV Campers- Measurements taken here are for one site only and are not representative of the whole campground. Each site will have a different length of feeder wire, some being relatively short. I suspect there may even be a few with longer runs of cable.
- The load used was an oil filled heater with three settings (Low, Medium, High)
- Measurements and resultant calculations are performed using the starting point no load voltage as the master with the understanding that the no load voltage fluctuates during the measurement cycle.Meter Readings with – Vellerman and Metex Multimeters(Westwood Current Probe used on Metex Multimeter)rman=120.0V, Line Monitor=120.1V
|
Stage |
No Load Volts |
Vellerman Multimeter Volts |
Line Monitor Volts |
Metex Multimeter Amps |
Line Monitor Amps |
VD Measured |
VD Calc’d |
VD % |
Dst Calc to xfmr |
|---|---|---|---|---|---|---|---|---|---|
|
Low |
120 |
112.1 |
112.1 |
5.6 |
5.5 |
7.9 |
5 |
6.60 |
577.8 |
|
Medium |
120 |
111.6 |
111.5 |
6.1 |
6.08 |
8.5 |
5.5 |
7.08 |
560.0 |
|
High |
120 |
104.8 |
104.9 |
10.8 |
10.84 |
15.2 |
10.8 |
12.60 |
566.0 |
(Supposition) It is possible that the line feeding the transformer is not sufficient to handle the load imposed by the transformer and the voltage fluctuations on the input(voltage drop), affect the voltage coming out.
The variations of distance could indicate that the line feeding the transformer may not be sufficient, and there is a voltage fluctuation into the transformer affecting the output.(This is strictly supposition.)
The Load is a ceramic heater (Thursday Morning with few people in the Park)
Using Chart Recorder
|
Amps |
Volts |
VDrop |
Vdrop % |
|
|---|---|---|---|---|
|
No Load |
0 |
124.96 |
0 |
0 |
|
Ramp |
7.0 |
115.63 |
9.33 |
7.4% |
|
Up to |
8.75 |
113.77 |
11.19 |
8.9% |
|
High |
9.625 |
111.90 |
13.06 |
10.5% |
|
11.375 |
110.04 |
14.92 |
11.9% |
|
|
12.250 |
108.17 |
16.79 |
13.5% |
|
Sample Software Calculation – Solve for Voltage Drop
V=104.8V, A=10.8A, VD= 120-104.8=15.2V
Software Calculator = VD = 10.36V,
Readings Taken at the Post ( Length reduced from 400 Ft to 300 Ft for Calculator)
|
No Load Volts |
Load Volts |
Amps |
VD Measured |
VD Software Calculated |
% VD |
|---|---|---|---|---|---|
|
121.3 |
113.2 |
8.46 |
8.1 |
6 |
6.70% |
|
121.3 |
118.3 |
2.68 |
3 |
2 |
2.50% |
Readings for a New Toaster Oven – T-Fal (400 Ft)
|
No Load V |
Load V |
Amps |
VD-Actual |
VD-Actual% |
VD-Calc |
|
116V |
105.8V |
10.7A |
10.2V |
8.70% |
10.27 |
VD-Calc is obtained by plugging Amps,Length into a software calculator.
Miscellaneous Appliance Readings/Tests
1) Test of Appliance Amperage
|
Device |
Volts(Off) |
Volts(On) |
Amps |
VDrop |
Vdrop Calculated |
Meters Calc’d |
|
|---|---|---|---|---|---|---|---|
|
Coffee Maker |
122.4 |
115.2 |
5.38 |
7.2 |
4.8 |
538 |
|
|
Toaster Oven |
122.5 |
114.1 |
6.36 |
8.4 |
5.7 |
531 |
|
|
Microwave |
121.1 |
106.8 |
9.46 |
14.3 |
8.5 |
608 |
M
Test of Low voltage on Microwave
- Ambient temperature 30 Deg Celsius,
- Time: 12:30 PM (Noon)
- No Load Voltage = 110.6V
- Loaded Voltage = 104.1V
- Function: Defrost 4 pieces of whole wheat bread.
- Required: 3 cycles of 30 Seconds at full power.
- Should take 20 seconds at full power.
Circuit Parameters – Test Circuit
Test Circuit with Reading taken at Site hydro Post
1. Our Theoretical Power Circuit is comprised of the following.
-
Transformer to Main Panel Circuit Breaker = 25Ft Unknown Wire Size
-
Main Distribution Panel (MDP) to Site Post = 320Ft of #10
-
Post to Trailer Circuit Breaker Panel (TCBP) = 40Ft of #10
-
TCBP to Device = 20Ft of #14
-
For Software Calculations the joint Feeder and Branch Circuit are 400Ft of #10
-
Readings
Calculated
Voltage(No Load) = 121.3
Voltage Drop = 8.1V
Voltage (Under Load) = 113.2
Voltage Drop = 6.75% Current(Amps) = 8.46