Precision Circuits Midi-PCS User manual

1
Diagnostics embedded in the Midi-PCS Including Factory Setup, Factory Test, Generator Amp
Limit, and 50-amp service detection.
Overview: Fully automatic Power Control System which requires little to no user interface. The display is
there to help the RV user understand power management and the function of the Midi-PCS. The Midi-
PCS monitors the total AC current of an RV and prevents circuit breaker tripping by momentarily shedding
up to five loads. As the user turns on additional appliances (such as a microwave, coffee pot, or hair dryer),
the Midi-PCS can shed the loads that it controls, (such as the water heater & air conditioner). As the user’s
selected appliances are turned off, and a minimum of 2 minutes has expired, the Midi-PCS will
automatically turn power back on each of the shed loads in reverse sequence. The Midi-PCS will constantly
monitor 120VAC RV power and shed and restore power to the five controlled loads. The display panel has all
the brains, a data connector to the I/O module, and an additional connector to control the air conditioners
through low voltage signals. The I/O Module houses a current sensor, two relays to control 120VAC powered
appliances, and Service Type detect circuitry.
Diagnostics: Press and Hold both the Select and Scroll buttons for 5 seconds to enter Diagnostics Mode.
In Diagnostics mode, there are four main screens. Pressing Scroll button
will step you through the four different screens:
1. Displays the Software Version of the Midi-PCS.
Press Scroll to continue to next menu option.
2. Displays Factory Setup option.
Press Select to enter Factory Setup review mode.
Press Scroll to continue to next menu option.
3. Displays Factory Test option.
Press Select to enter Factory Test mode.
Press Scroll to continue to next menu option
4. Displays Exit Factory option.
Press Select to Exit Diagnostics.
Press Scroll to continue to return to the first display.
Display Panel: PCI# 00-10050-000
I/O Module: PCI# 00-10024-000
1. Display Screen
4. Screw Terminals
2. Select Button
5. Current Sensor
3. Scroll Button
6. Connector to Data Cable
Factory
Setup
Factory
T e s t
E x i t
Factory
S W V e r
2. 0 5 - 4 2 1
MIDI –Power Control System Factory Setup & Test

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Factory Setup: Pressing Select while Factory Setup is displayed brings the user to this display.
This is the 18-character RV Data-2 Reference ID spread over two screens. Press
Scroll to get to the second screen.
421Winnebago170151 is interpreted as follows:
421 matches the last 3 digits of the part number, for example 00-10050-421
Winnebago170 identifies the RV manufacturer and model
151 identifies the revision of the RV Data-2 as year 2015 release #1 of that
year.
This is useful information in case the Midi-PCS ever needs to be identified
for replacement.
Press Scroll Button to move to next Display.
This displays the Checksum of the entire RV Data-2 file. It can be used to
confirm any data corruption. RV-Data-2 file contains the personality of the
Midi-PCS which includes RV Model specific information like appliances to
shed, how they are wired, Generator size, and if 50A service is enabled or
disabled.
Press Scroll Button to move to next Display.
This is a menu option to review appliance Shed Order.
Press Scroll Button to move to next Display.
Pressing Select Button takes user to the Display below.
Example: The 1st appliance to be shed is the Electric Water Heater. Most likely
it is the least important appliance and will also be the last one to be turned
back on. In the case of the Water Heater, the LP heater will heat the water
when the Electric Water Heater is shed.
Press Scroll Button to move to the next load to be Shed.
Example: The 2nd appliance to be shed is the Refrigerator. An RV Refrigerator
will automatically switch to run off the LP when electric power is removed.
Note: Shed Order cannot be modified, only viewed. It has been carefully
planned by the RV OEM. The same information can be seen in normal
operation mode since loads are listed in Shed order.
This Menu will allow you to modify the maximum amp limit of the generator.
Note: This screen is only available on SW Version 2.05 and above.
Press Select to move to the screen below.
Press Scroll to move to next menu item.
This screen shows the current amp limit before allowing the user to Edit.
Press the Select button to begin modifying the amp limit.
Press Scroll to exit back to the Max Amp Screen
After Pressing Select you will see a cursor flashing in the ten’s place.
Use the Scroll Button to decrease the value. Going below 0 will loop you back
up to 9.
Use the Select button after you set the desired value to move onto the one’s
place. Repeat the same steps for the ones value. Pressing Select will exit the
editing mode.
00 = Disables load shedding and does not display amp draw.
01 = Disables Load shedding but continues to display amp draw.
Press Scroll to move to the next Display.
Press Scroll to exit to the Max Amps Screen
G e n e r a t r
3
n
A
4 2 1 W i n n e
b a g o 1 7 0
151
C h e c k s u m
0 x B 7 8 6
S h e d 2
R e f r i g
S h e d 1
W a t e r H t r
S h e d
O r d e r
G e n e r a t r
M a x A m p s
Generatr
30A
G e n e r a t r
n
0 A
MIDI –Power Control System Factory Setup & Test

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Factory Setup Continued
This Screen is used to Enable or Disable 50 Amp Service. The default will be set
to what your RV is designed for.
Note: This screen is only available on SW Version 2.05 and above.
Press the Select Button to change the Service to Enabled or Disabled
Press the Scroll Button to move to the next display.
Press the Select Button to Exit Setup mode.
Press the Scroll Button to return to the top of this page and Display RV Data-2
Reference ID.
Factory Test: Pressing Select while Factory Test is displayed brings the service technician to this Display.
Midi-PCS can control up to 5 appliances, (+ 2 additional future relays)
This section allows the user to manually control each individual appliance,
shedding and restoring power to that appliance. This is a great way to test the
vehicle wiring for each individual appliance.
Caution should be used, because turning on too many appliances can cause
over-current and the circuit breaker to trip. Midi-PCS does NOT monitor RV
current and perform energy management while in this mode.
Pressing Select button toggles the appliance from Powered to Shed and back
again.
Pressing Scroll button advances you through the 7 potential relays that control
the appliance.
Note: If an appliance is not wired to a relay, then that relay is also not named
and will be displayed as below.
Relay 1A - Relay in I/O module, L1 the circuit breaker input, & R1 connected to
appliance.
Relay 2A - Relay in I/O module, L2 the circuit breaker input, & R2 connected to
appliance.
Relay 3 - Relay in Monitor, low voltage control of AC compressors.
Relay 4 - Relay in Monitor, low voltage control of AC compressors.
Relay 5 - Relay in Monitor, low voltage control of AC compressors (Optional).
Relay 1B- Relay in I/O module, L1 the circuit breaker input, & R1 connected to
appliance.
Relay 2B- Relay in I/O module, L2 the circuit breaker input, & R2 connected to
appliance.
Note: Relay 1B and 2B are reserved for future use, if a second I/O Module is
installed. Not presently supported, but controllable on Display.
For more details regarding the above relays, refer to the wiring diagrams for
your specific RV, which can be found at PrecisionCircuitsInc.com
E x i t
S e t u p
5 0 A S e r v
D i s a b l e d
5 0 A S e r v
Enabled
W a t e r H t r
S h e d
R e f r i g
S h e d
Relay 3
Powered
Relay 3
S h e d
R e f r i g
Powered
W a t e r H t r
Powered
MIDI –Power Control System Factory Setup & Test

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Factory Test Continued
Once all 7 appliance Displays have been scrolled through, pressing Scroll will
bring you to the Service Type display screen. This is the same is the Service
Type display in normal operation, placed here to make sure all Service Types
are tested during Factory Test.
1. Unplug the RV and “No Service” should display
2. Plug RV into 50amp Service and “Service 50A” should display
3. Plug RV into 30amp Service and “Service 30A” should display
4. Start the Generator and “Generatr ##A” should display, where ## equates to
the Generator capacity, example: 45A equates to 5500W generator (5500watts
/ 120volts = 45 amps)
After testing all Service Types, Press Scroll button to advance to this Display.
Just like in Normal operation, Midi-PCS displays total RV current. Turn on a
few known appliances and observe that Amps displayed is reasonable.
Alternatively, a clamp on current meter can be place around the same wire
going through the I/O Module for an exact current draw comparison.
Press Scroll button to advance to this Display. Reference Voltage is an internal
reference used by the electronics and must be from 2.44v to 2.54v for the
Midi-PCS to properly operate. There are no adjustments, if the value is not
within range the Display Panel should be replaced.
Press Scroll button to advance to this Display. Battery Voltage is not an
accurate measurement of the Coach Battery, but instead shows the level of
Battery power provided. Although the Midi-PCS operates outside these
ranges, it should be between 11 volts and 15 volts for most accurate operation.
Pressing Scroll one last time brings user to the end of the Factory Test.
Pressing Select Button to Exit Setup mode.
Press Scroll Button to return to the top of this page and restart Factory Test.
Note: Upon exiting Factory Test, to ensure all relays and functions are back to
Normal operation, the Midi-PCS performs a soft start function. All
appliances are turned off, a 2-minute delay is executed, and then all the
appliances are individually restored.
A m p s = 2 5 A
R e f V o l t
2 . 4 6 v
E x i t
T e s t
S e r v i c e
30A
B a t V o l t
1 2 . 8 v
MIDI –Power Control System Factory Setup & Test