OTTAWA -- Police are warning Canadians against abusing the 911 emergency number in connection with the testing of the national alert system.

The warnings came Wednesday as wireless devices, radio and TV stations were set to broadcast emergency messages as a test of the system.

In Ontario, police services in Peel Region, Barrie and Sudbury asked people not to call 911 for information about the test.

"Using 911 for non-emergency calls could delay help for people experiencing real emergencies," Barrie Police wrote on Twitter.

The emergency alerts have become a familiar sound since the national public alert system was first tested in early 2018, when glitches were uncovered in several provinces.

They are designed to warn of imminent threats or emergencies, such as floods, tornadoes, fires or Amber Alerts.

Some alert recipients, however, have considered them an annoyance, sparking complaints on social media -- and even calls to 911 operators -- that the emergency warnings woke them up late at night or were targeting the wrong geographic area.

The complaints have prompted often heated debates about their necessity in helping to find missing children or to warn of emergencies.

Depending on where you live, the tests will be conducted mid-morning or early afternoon Wednesday.

Since January, the Canadian Radio-television and Telecommunications Commission says 130 emergency messages have been issued, warning Canadians of potentially life-threatening situations.

The CRTC said the emergency alerts have been credited with saving lives.

Pelmorex Corp., which operates the system's technical infrastructure, says the tests are necessary to ensure the system is working properly and to educate Canadians on what the warning signals look and sound like.

To receive alerts, compatible wireless devices must be equipped with the latest operating software. They must also be connected to an LTE network when the alert is issued.

All wireless devices sold by service providers after April 6, 2019 are required to be capable of issuing the public alerts.

Canadians with compatible devices who don't receive the test are being asked to contact their wireless service provider.

Here is when the test signals are scheduled to be transmitted:

Alberta 1:55 p.m. MST

British Columbia 1:55 p.m. PST

Manitoba 1:55 p.m. CST

New Brunswick 10:55 a.m. AST

Newfoundland and Labrador 10:55 a.m. NST

Northwest Territories 9:55 a.m. MST

Nova Scotia 1:55 p.m. AST

Nunavut -- No test

Ontario 2:55 p.m. EST

Prince Edward Island 12:55 p.m. AST

Quebec 1:55 p.m. EST

Saskatchewan 1:55 p.m. CST

Yukon 1:55 p.m. PST

This report by The Canadian Press was first published Nov. 27, 2019.