Just to be certain, it's a mag ballast, no? If an e-ballast and the lamp is still good, you may be sol!
PROBLEM 1— LAMP WILL NOT START
POSSIBLE CAUSE
CORRECTIVE ACTION
1. No Power to Ballast
Check fuses or other causes of power outages.
2. Normal End of Lamp Life
Often the simplest procedure is to test the lamp in an adjacent fixture which is known to be operating properly and then replace as necessary. It should be kept in mind that series ballasts will occasionally extinguish the adjacent lamp if one is removed.
3. Lamp Loose in Socket
Inspect the lamp to see if there is any indication of arcing at center contact button. Tighten lamp to seat it properly. If base is distorted and will not seat properly in the socket, replace lamp.
4. Optical & Other Sensing Devices Inoperative
Replace sensing device. (Check this by covering sensing device to block out light while power is applied to fixture.)
5. Defective or Improper Wiring
Examine wiring to ensure it conforms with wiring diagram on the ballast label. Check primary wiring to ballast and from ballast to socket to establish circuit continuity. Check connections to see that they are secure. Check for under-sizing of wire gauge, resulting in lowered voltage. Repair circuit.
6. Voltage at Fixture Too Low
Measure line voltage at input of ballast. For most types of ballasts, measured line voltage should be within 10% of label rating. With many types of distribution systems, increased loading or demand decreases available voltage at the ballast primary. Therefore, ideally, a check should be made at full load. If tapped ballast, match ballast tap connection to supply voltage measured at ballast. Increase supply voltage if feasible. Verify that lamp to remote ballast distance is acceptable.
7. Incompatible Ballasting
Correct ballasting is essential for dependable HID lamp operation. Any HID lamp will perform erratically or fail to start on an incorrect ballast. Make sure that the ballast label data agrees with the line voltage and lamp used. Incorrect ballasting will generally cause a lamp to fail prematurely.
8. Defective Shorted Ballast
A shorted ballast will generally cause the seals at the end of the arc tube to rupture with an indicative blackening in the seal ring area. Shorted condition may be due to shorted capacitors, shorted leads or shorted winding. Replace components as required.
9. Improper Lamp Operating Position (Metal Halide Only)
The operating position should agree with the lamp specifications. A BU-HOR lamp can be operated base up, vertical to, and including the horizontal, and BD can be operated base down, vertical to, approaching, but not including the horizontal. A lamp operated beyond the specified position may not start and degrade lamp performance if it does start.
10. Lamp Has Been Operating : Cool Down Time Insufficient (Hot Restrike)
When HID lamps are operating and the supply voltage is cut or interrupted, the lamps will require a period of time to cool and re-establish optimum starting conditions. Bare mercury and metal halide lamps require from four to eight minutes cool down time. High pressure sodium lamps require approximately one minute to cool before restriking. In a luminaire, restart time varies with the degree of ventilation built into it, ambient temperature, and draft conditions. The time from cool to restartable condition can realistically range up to 20 minutes for mercury and metal halide lamps in tight luminaires.
11. High Restrike Voltage (Metal Halide Only)
This condition is peculiar to the metal halide lamp. It does not occur with mercury. If the supply voltage to a metal halide lamp is interrupted during the warm up period, the subsequent restrike voltage (voltage required to restart the lamp) may be higher than that required for a lamp which has been allowed to stabilize (come up to full output normally) or to cool down to normal room temperature.
12. Improper Ballast for Lamp Operating Conditions Environmental conditions such as extreme temperatures, high humidity and other factors affect ballast operation. Check lamp environmental operating conditions against published performance.
13. End of Ballast Life
The appearance or condition of a ballast may give a clue to whether it is good or not. If it is charred, it may have been subjected to sustained excessive heat. Swollen capacitors indicate trouble. Check with appropriate testers, ammeter, and voltmeter. Frequently, the failure mode of a ballast is capacitor failure with consequent low power factor operation and high current. This leads to overheating of the core and coil and eventual failure.
14. Defective Ignitor
Insure that the lamp is good. Disconnect the ignitor and install a specified test lamp. If the test lamp lights, the ballast is good but the ignitor is not. Replace ignitor. If the test lamp does not light, the ballast has most likely reached its end of life.
15. Mismatched Ignitor
Verify that the ballast and ignitor are matched according to the specifications. Replace if necessary.
16. Lamp Defects
Common defects that require the lamp to be replaced include:
* Arc tube leak
* Open welds
* Probe or cathode moly electrolysis
* Diode or switch shorted
* Quartz devitrification around rod
* Sodium leak
* Open diode
