Maintenance Service Sheets

[Freecool]

Hi I am currently trying format a a/c & vent maintenance tick sheet just wondered what type of maintenance sheets any of you use would be grateful
of any feed back.

Freecool

[sinewave]

General Air-conditioning Service Schedule
(Scope of Works)



a) Clean or replace filters as required.

b) Inspect and clean condenser coils

c) Inspect evaporator coils and treat with anti-bacterial agent

d) Check operation and setting of HP switches

e) Check operation and setting of LP switches

f) Inspect condenser fan motors

g) Inspect evaporator fan motors

h) Inspect Vee belts, replace if necessary

i) Run and test humidifiers, manually drain, change bottle if required

j) Inspect incoming electrical connections at the unit

k) Check all electrical connections are tight

l) Check operation of expansion valves

m) Check operation and setting of head pressure controls

n) Check refrigerant charge

o) Check sight glasses for moisture

p) Check operation and calibration of thermostats

q) Run system and check air-on and air-off coil temperatures

r) Check for oil and gas leaks

s) Inspect cooling towers (if applicable)

t) Check overall condition of the equipment

[Freecool]

Thanks: Sinewave it gives me something to go on.

[MJF_07]

Bloody hell sounds like an annual that. . tick sheet, is that not a monthly check?

[marc5180]

How would you check operation of LP and HP switches for the Hp id imagine turning off the condensor fans but Lp? Also check operation of expansion valves? How?

[lana]

Hi Marc,

For LP testing you can pump down the system by closing the receiver valve or liquid line hand valve.
The LP starts to decrease and when it reaches the LP setting then it must cut the compressor out.

To check the TEV operation you have to observe the LP with superheat. With little experience you can "feel" the TEV's operation .

Hope this helps.
Cheers

[marc5180]

For LP testing you can pump down the system by closing the receiver valve or liquid line hand valve.
The LP starts to decrease and when it reaches the LP setting then it must cut the compressor out.

Of course, i didnt think of that. as of tomorrow il be testing the Lp switches as well
Cheers Lana

[BigJon3475]

Anyone wanna shoot down my service list???

Air Conditioning Checklist and Records.

Address:________________________________
Date Started:_____________________________
Time:___________________________________
Size of system:___________________________

Thermostat:

Model # and Name:_______________________
Type:__________________________________
Is it Level?______________________________
Temp On/Off (actual vs set)?_______________
Heat Anticipator Setting:___________________
(Use Ammeter between R and W/Use
10 wrap method if Needed Don't forget
to divide by 10)

Condenser Readings:

Type of Refrigerant:________________________
Amount Used or Recovered:_________________
MIcrometer Reading:________________________
Condenser Model #:________________________
Condenser Entering Ambient Temp:___________
Condenser Exiting Temp:____________________
High Side Pressure reading:__________________
High Side Line Temp. @ Service Valve:_________
(Subcooling)
Low Side Pressure Reading:_________________
Low Side Temp. @ Service Valve:_____________
(Total Superheat)
RLA:_______________LRA:__________________
Capacitor uf:______________________________
Ohm Reading of Comp:C-S:___C-R:____S-R:____
(Hi:S-R Med:C-S Low:C-R)
Ohm Reading To Ground:____________________
(Use MegaOhm Meter)
Amp Draw @ Compressor Run Winding:________
Amp Draw on Condenser Fan Motor:___________
Voltage Into Contactor:______________________
Voltage Out of Contactor:____________________
Cleaned Condensing Coil?___________________

Evaporator Readings:

Clean Evaporator Coil?______________________
Vacuum Unit of Dust and Debris?______________
Vac. Entering Return:________________________
Oil Fan Motor?______________________________
(20 Weight Non-Detergent)


Cooling Mode:

Low Side Exiting Line Temp:___________________
(Useful Superheat)
Evaporator Entering Ambient Dry Bulb:__________
Evaporator Entering Ambient Wet Bulb:__________
Evaporator Exiting Dry Bulb Temp:______________
Evaporator Exiting Wet Bulb Temp:_____________
TD Across Coil Directly Ent. and leaving:_________
Temp. Exiting Vents: (Wet and Dry Bulb)
BR1______BR2______BR3_________BATH1______
BATH2________LR________KITCHEN_________
Pressure @ Vents:BR1____BR2____BR3_________
BATH1____BATH2_____LR_____KITCHEN________

Heating Mode:

Voltage @ Heat Strips:L1__________L2___________
Amperage @ Heat Strips:L1________L2___________
Total Wattage for Heat strips with fan on:__________
Temp. Rise Across Heat Strips:___________________
(Not in direct sight of heat strips)
(Watts x 3.413/TD x 1.08= CFM of the Fan Motor.
Use to determine if cleaning is needed or Replacement
is Needed)
(Ideal is 400CFM per Ton of Ref)

Emergency Heat:

Voltage @ Heat Strips:L1 to GRND____L2 to GRND____
Amperage @ Heat Strips:L1_______L2______________
Total Wattage for Heat strips with fan on:____________
Temp. Rise Across Heat Strips:______________
(Not in direct sight of heat strips)
(Watts x 3.413/TD x 1.08= CFM of the Fan Motor.
Use to determine if cleaning is needed)

Signature:_______________ Date Finished:____________
Items Used for Repair/Replace (Cost$):_______________
________________________________________________
________________________________________________
________________________________________________
________________________________________________

[lana]

Hi bigJon,

High Side Line Temp. @ Service Valve:_________
(Subcooling)

Hi side line temp at service valve is the discharge temperature and NOT the subcooling.

Low Side Temp. @ Service Valve:_____________
(Total Superheat)

Low side temp at service valve is the suction gas temperature and NOT the super heat.

Sub cooling = condensing temp - liquid line temperature after the condenser
Super heat = evaporator outlet temperature - evaporating temperature

Cheers

[lana]

The service valve on the type of equipment HE works on is at the outlet of the condensing unit on the liquid line.

As I understood he meant the compressor service valves.

If what you mentioned is the case then still that is the liquid line temperature and NOT the sub cooling value.

Cheers

[BigJon3475]

The service valve on the type of equipment HE works on is at the outlet of the condensing unit on the liquid line.

The term 'useful' superheat is unusual but he has already covered 'real' superheat.

Correct.....I have service valves right outside of the condenser. Only residential work.

These are things I use to determine problems. I would use useful superheat and total superheat to understand if I think there is a problem with the lineset (meaning insulation is gone)

[BigJon3475]

Hi bigJon,

Hi side line temp at service valve is the discharge temperature and NOT the subcooling.

Low side temp at service valve is the suction gas temperature and NOT the super heat.

Sub cooling = condensing temp - liquid line temperature after the condenser
Super heat = evaporator outlet temperature - evaporating temperature

Cheers

Those are the methods I use. I use the term subcooling and superheat incorrectly I guess, but since I know how to achieve the superheat and subcooling values I use it as a ref. instead of a description on "how to"......This is my personal checklist and it can be changed as fast as I posted it up. That's why I was looking for suggestions or comments and also provided what the original poster was looking for I hope.